CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="390"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "help.medium.com",cType: 'managed',cRay: '913521e17819fd94',cH: 'ot5fUNdqE.o6MjLT_F2qfj0jMcfaQazrbrJNB2wcpF8-1739788544-1.2.1.1-ByAWh6xT8CrrGeMAsakvNidyHlpRryxKQ0QZXrd4GVuds8tI31IcAmu0223fKWG0',cUPMDTk: "\/hc\/en-us?source=post_page-----dde180716096--------------------------------&__cf_chl_tk=NiJTV6h4QNl0PCoUSyFBfmIYVzMztvegqPVPEOnCScc-1739788544-1.0.1.1-LXSk2ZcQ25t.ZOyKWBDGOhcP5pXlnikYQm52dX39Q2s",cFPWv: 'b',cITimeS: '1739788544',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/hc\/en-us?source=post_page-----dde180716096--------------------------------&__cf_chl_f_tk=NiJTV6h4QNl0PCoUSyFBfmIYVzMztvegqPVPEOnCScc-1739788544-1.0.1.1-LXSk2ZcQ25t.ZOyKWBDGOhcP5pXlnikYQm52dX39Q2s",md: "UG44OtFKlyQzAxBSTGjjWFeiTDA.yuml7u.6M9rthts-1739788544-1.2.1.1-a5MJ7b9yQB1td286RAdZ6jBkkEITMsmDEiPvlm_vxgtvSR.NjlKL9eUlO9SZxjK5fzxgHgYtFpsjBwCnX7QgSxAnsIeTDj.iWsh7HPAcWhoCO0zKo6mdNxJP5qCXTP5whDzs4up0YgM9uv85TYwKiFiK3pH3SbC3uA4CceoVhQMMhbyixFILz3vt6ly9hIxfucduc4pk8_lfw7RbdNvj0vq5hLiq88yOaSkLWBAs6McWHYX2j2iIMgty2EeuYqVbAwNnrYW1tgJQeM2WITqsZdE.wdCnsRX5_KTm.PIZsCKY5WR3vALcJeaHIu1jvk6YwgJ7ZNIPuuSCg3zrMpk9isQIRxon_W5GrQNlWh6zaq5I8Y5bB9w2soseaEFM51bswNweZNqPPMFDArmTCdgql3GNpvnwL_VZWT4j9Sff_XDG8MafsjDZohSYYe61KE9upDnQjrDjdXIlSRckGuojauWWVFeA7eg6U4WhDRbe4OLh11tMVUcmq8EXdfgGSDnZ2I4lkaT5CZNq.MLP1NN1BXxgks1IGF88z3A4wZZWuJdtBQJDDzkOkjdA6zIgYeXwTV51MCEGQZQgC_78B.Rl1KSSCiLVufPd7GdorVd.6Bsh7dx29OpEvSJ5ZkrorvPhxg3SoU0tqzHl4UTY4ZdMGkkxzQBWiV6imiKFOgfN0w9YbAS40dEZPvCZ27UxUTZZ_DHxCqy104Yg90ntee3_GTyVlOelNkP6qJkSmAeKuSleCK0EM09VSWMXmubxvY.NWL6_tgGoGL6IWE9i.wWsQAF7riaRQ4mGs5EBiS9NXluyj_EvlVEv14ZxG_PUoY9tSUt5yV.eg_9qwdQIy13JdQ9vu4gd4lx3agvSxCK3mgJHXatA.lItOEpyNBDracvtVdLI3yLDdAIcTTtAoa1xkQlyAsAnGiGQKNvwAo34UEX7FR078YI44TK3SNmwvvyObgY.tNqeXm8CD0XxaygsAyso2LezTIiuR9tzh37OUs5pYHQrJEwydbbpdW5ayXVB2DZll1HgREzc7yXeIBgTvsIQK7SJDruE6IJ4ynZ3IqYTo4PI9sURuv3GMphGBhgd8R1gDTWjl2_GIfQ0MK7ueOsLbSyqgTM0mGvDKakitCPDxjJ8Ia7khOpcNxOyeZJXofwvjKFsinpDB6KbQ8C7zDTJXmwDXdPUVScqiXEx2daGm_pirfskvwXwNWn.a5wxxH2ZvJqDPfHBTiiaM..WLPnt.FYmqsu2n3JFU4AUwyITFRPrM4cL_E9P2zY9BX3HxkFSPRwRhxau7Nseg2Go3JzWw_NByTtxYkCnoujWgSpr_ILmVfkdXxOEzc2quqVRErrdRPiGJTl6e8q6uv1IZ903m1g2CDNNQqiLapyhbNMbF_QC5b4_nj4I0xhUmO2QAsF4Ih4GX_A9Ns0AYFPgHkRn8WPVleRb6M3Twr_ZLNNQkNuUPt_qaEJaRogs.oYx7zB4dQHo_MC8huRrzNalH.390GDXfiG4ij2Kt.qDoq8oGWwpc_tNGF16WxmomxH8GDuLaPyGJ077CkqLaQJbNTxkNTsII85_sHyYqC_XyoPjKAQNiJEgGMq0Ls1XM4eRdDfc7u9wX3iFismo1e0f5E9kLsPogs7mrjKZDVp35au9mBnxh_pfYmURa3JVfTm4ao6tgjOpesdNApz5twv_UN_H4dlQEW.kZVC7mFAAc8euT1hOs.q2JUD9KpBIYY4sYVrBimOY4azsXQf6AVxF1FZ1f.LCI0u2hgS_sY2RkgVDH6BJj_7fGKRTS1LGD79ZBviS4a5rq3ZsFMYw10CEv3I6Rs_f23.hltYX2MR3IaML4YpUldearDZB.ncRn8AcJtB_eR9BozZS2sApFbeTjb99iDdgNbm0_vK0UHtru4EBUSViZCYIY9AvGnlW2h_lqjcRzqLPz_oYoHxOvYXR9FufJIB8.XA7cU.uLMlRlwY8EMIvv6_uf72Qsa6EtaJdgGbtFM1iLOUoR4mhV_tY1iRLbeWTvN50jE2INPjCI6K57WMzJdoUmlVQ.TPQZXs.pVniQKbtovxjK1f1myT1Qji3OXW52ngXTDhZLf2N1fcu8f7s.N4dcnmD0HKh.izWbofgFBNP2YdJPUccbE7eUuHltTnrvTKPWBw37W7wtzEFVWWZV0QR6sjRJEyDmWZ4h9OVQ.d2Ud0kLsJFklNek8k5Cve4tMXa0kbxvu1Q5I9TYBg1oHtCiydGhvmVQfQ9rs223NjVfvHUoRAhfFojXY4KHglI15nvtAa_DwiPR.FrHpm30faLG09CEnqYCE9C0Gdy7Mz7oPm_LFE0hsHC.UE_VuYV0npsdlXJLVHej9RQ_sHlpdwoAnOIgVgSA2eiOecZjNDFrXIyOWSISj.O_vSv8nDRBiUxJF3WoHxqWUeqMyM1KukEA6V3kUZQt3UXbwFhNWPUpt_McyeYQzgQC_vu38mLW6dAZMRrifCxKlwhtC7z.zA4Lnt9YHQdu8cFMGf2LUOCX8iyECWrR77uG_NYC0L1dMeWPKYZiz0REDjwiOdPWvGp9mse4vBQX2150lZVhaVQAmOX4dg4krylVPOGwXvG2uTj0x2bx9UlCbhC__Ar23C7kJCC7wwv88zpYeU9pgc1ysYd1WJTNdvA7NqykBDnP.YmXTbl7EUXJzsRKvtjD0MCsMtaPvCoLNWR",mdrd: "rVcbRNIWhP509k6MPNDytD_Zb0ptYfJAgolG5YztYaA-1739788544-1.2.1.1-MPWniutId3JdTxoNZpy19DadZpOkdTs9eHYZZwcByHT0mpaW7GsYJz3jkQvdEpuuQ1XNnkv5_mSOn_XMznvaMUV80bmrbMHuleKEoRYSgjaIcCBBy3zfuUB.XUpiTxeRZuW_gicTfOUw81iYf2ps01_PR5UQmb11._ICVH4MS7lSvjrneDPjzpd29nuJbdOxyJPlb1DAkJQbsOxaw6_dKlH74BsWgHuRXocYI7Kldx6dj6tJMwMHEE5BvO4xgupOtAseu.nqNc8ULbHC7901RVGT2IBzY_LDj5HM5uC0cVQ0SuHUFumfW3GS1hSSUFG58BzmE3faahLGzIZ5jGZvjPSgCxFzMqH4knidHakp7hWXiqHYIIB8FgJUUMRkpz62Saii9FkX6hvHIhUMmJTbliogUmhw6G8b6etESqPbO8VH2xo_dUt1VzlW_A10zWNTIl8Q5z21GPJXfULCZTs9YiXneu3LsLEBBx_BeSenV3RSo7SpafMCH2PBT4z992wHNDGNewiKAwZteHbbaeQI9vFnOFGbg.e7krkEcoX.GmVxnU7pT2iA8mP_RX8p2LuSnPpnt77SkL_qOB0s5KA4aJYUdug7qR2PlZuOC7EtiTSQxNP3ldzda2byaKtyZ4pPmTV9rnSvUuB6hpuupIdMKfeGVTy44B6rivyzjOTsVNYGQzRzdj94Ndgq.y8q8Uk0R9vOMwtIuSPib2Fa7TI9rBIHhNbqZ3jEC_ZtZjWIS__fWVMTe6dQbqzJyRsLrYN0AG8rxVaYDXA_29DMAbFX9x_DM2MRHKCs9aZn58TFwvK0AgWon7k7DLiCefv.ij5npYU31NuXCL1QEG3CHLSHocVtTzp8aa8MXsB81BLt1UNtjJVwrtP_4Lq.rEyuSzwXqx7.lAMe8A3edPYWWCr.nfOw16zgDWaJwIbF_oDMSAP9dwGhwMjSqCwNOxP8CXIkhSOhXeux3PonnJznCKCHpcpIZQdKCxtxGOgCu0cBrh_cq8eQcBQqZSDoPwEpYjPwdHgqQkPT1g9kpTIk7BpRVM8NbQBoPQ9_6If_fbGWxwlUG9WjaTaivLR09agEWjQVmU.t1M22g9qol.RwWDhcx6hTSMXiH4LL5GQlQkr7YjSwRc.6fNvjefXa9TI2PZZoGo_eld_O96QfvEJcAOpldx1DM8QVrBnxiaNFYyVTYPwGrastxZ0i2Bl4QZ811R1xMV8oGX_Gc_clYbcH4y76U_Q02y3SpSCfU75mG5Of4kMTY5LCZBPNGQ9wDyIsuUx_yuuUbSwJYwLl0k2d3UzzxYJ3TtoVL2243FrIMF7K5qQNbjUuE0uuTNr1kxBDK8o3D4JrijHtoBPmsY68ogxJ4cIgHPywU8CSc4YG1STmrulG8iY.qM8X3Bke7jjBTSf_iuP9s6ctu6XzJRKeXE4UK8VC5xY4nue1SJvZT.FeRxYlERKt8U4i31UMiots0mfnkgewNeic65bcLYA0UfS1jDiFSmwggZvgprfNNRwXQ.b480t.3e5XbRSmoGeFciP3cLItNWEOEvi_FXKAv4Kzljb_vESa82B2yO4VKlj0anGNY_cd7WYHllk_U0Ht6e7x2kEREEyA_4KydBkht_SluMBs6zoiutQ6m_qNoUMCmSsuEAXcyfB9CoavjIcMkwvT4v7I90zJsViXPQG9AoybH8sS2cGAbNgSr1tESg4gD0xzgtCy.JlQmg9uDerqNk_769Xccre.Cx1TIA0y1Nb4XRepZxB37DZj00k4cqBBGakhUTfEOnB5EEnTK_2IQswudgbtQpXrdZ83PH8uzIAjdGtrrOYg3RB0OdxujmEuHYMJUYs0f2WyDCExmJEFYz3A4pkk2Q0yDhBGlgcWsaqXdoYJULKTLvfOiMcRigZ6bEexzKhbPOAU2TR.bdfCcDcI2muHLq8lkIWp1wdPws897nZ08XAbmjctDGX5LvzhsQ97mDGZn3Ila4vR9ROqTMgk"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=913521e17819fd94';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/hc\/en-us?source=post_page-----dde180716096--------------------------------&__cf_chl_rt_tk=NiJTV6h4QNl0PCoUSyFBfmIYVzMztvegqPVPEOnCScc-1739788544-1.0.1.1-LXSk2ZcQ25t.ZOyKWBDGOhcP5pXlnikYQm52dX39Q2s" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>