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: "www.ap.org",cType: 'managed',cRay: '921139845fa1fd71',cH: 'yHJ8P8f.lf_Iemo2IhF9O7mdTMBI6PVw81oiKxOcB1Y-1742096379-1.2.1.1-2Q5uiZCZ5BLK7HYcxQy9YHIq3T1Zok9d7F.wdyv0sBusMecAmtdpgYx9aSL7YlOR',cUPMDTk: "\/solutions\/?__cf_chl_tk=6_2LRzyOTl_KJQzxA_WKNQGT.NxHYkPNV7wm6qjwuv4-1742096379-1.0.1.1-tJA.Xe5asOwK9Z5DZT_BOL0u4NN4sfuyYuKbqhP_cg4",cFPWv: 'g',cITimeS: '1742096379',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/solutions\/?__cf_chl_f_tk=6_2LRzyOTl_KJQzxA_WKNQGT.NxHYkPNV7wm6qjwuv4-1742096379-1.0.1.1-tJA.Xe5asOwK9Z5DZT_BOL0u4NN4sfuyYuKbqhP_cg4",md: "sLYf2CtjiLFBRcziWsUkLVjrSNxteHcw7OiHcIIlluk-1742096379-1.2.1.1-p0S6SNWlrWFytMFCT4AG4eLSUVlGvVYcmLPtgKIU8L4Lr1mEs7fuZKx6Vk0D2JkSIEcymmEmrafLUwqLbnwx2fwztvd52i.mA8ZsIEZinao52YO8Vzjp7vasK_08DmaFOwqpNKGHMWWi8lTgYwfhT8t2g8Gnds0NiwRhWMqQErpWnzZSNIP0p6mjfPiHBqLms9.i.iOqZzgtAoYwqLveQIZKp1CAyqIBGbKXGZRZPNKpfICs7RdXP4j8cytldIYGUO5MaiK7p_FULsqN_LwnHMKuaCaSGZ85meIHblvJwDw9ZYGfgVA6N4xyaZbh5FXtrm8cHiv4r75nZXAXyURLZokrYkcvM9cAig6PinzHHXW_5Gxtugaga4_KT9RkbJsqseGFDLFmiNj1WpCnUXoVcpd968EBx4H2Lz3V0uwZS6M09vv6oZcz6b_e2NwtG0Gia8mMHnYi8yPelTgpj482fJ0pu8zflBpLD6oxXULUWWL8btGz0fFLea.97rpYvf7e8W7htng9hbtDk_BNLq_.ZiAHKZ7kd3FNuyMlE6DRP0H0Tx.Xa9P3WocbUZ6WuQmexQUTFNQyHOQ6gK4MuDFo.J7OzLW7kb2GFbLj4GGJaUnjzzi3AVIqaA9F4w5rF9Sb_z4ml0s46lODPYuiLXtpKyJfT6xBD_rkrhYqXbZIut.9MU3E6bSgCHW4jO.O0ziKNpch0lk3DX30KKaSjGNS246Wij1qBbiI9JSiJ5YCM6zFYfLcSuSj9z.WFS_atPF8D2SuFuHS3Udv.diS5AapndrRIro_MjVfSVG3RzCUZc32u6Qz97mIIl2lteoCzyFZvzlJbYoxsU4cAExZJ..zsfUq6S2lrL09.SzcQIo4a2MsoOokbV2E4VoDbWbgJLe63MslEI.TA4s9.SAGFzwFCyGuheb7Pe82eXFG3RtJLYBw7hw48lOmHtzlWEYC1gru4UYdx2oJ4yrltZdxa1mX38YI33enjpoDhz3XxxKsLKPc4u5_ksDfHrS3Tsdih9rtufXA49EpsQs6kCNd_mpO.1UdA4lJEVS0P7Op9m_tc5kfJrSlkKaJqoOZ73939Tlq9lUkvNPhU5GEh_Qg1ddylxQmecldO522JCJO.ghBy0DC.NMy8LSoLyR.ElWBkvCaYwFQQEwU1_t_yzSVS1IVbStM4.8lTPFb8LFqqp81JGQJqjDoG3KokUvOHkOBRP26LiCtdMZ8hAa8SxtBvDpNZB.ay4pW8WLl6MvSpEF0avA",mdrd: "c41GxZ58zS.x87Ai8TRyh05A1wSkOW9Cf1FYMbC6hiA-1742096379-1.2.1.1-CMER58scP3Exl_Qr4OqaK.ACrIrI9tTTpp9hFrY_2VBboxJR78YsMgLedGY7dZ2Co3Bu5Mp46fbD3J1I9Wa6eais.t.1OuMERsirCu_yNUb4UWit70WZUElOSccAZmZzFbxA0qAnZIRWRMQkDKY5yExaI4FZZcexXAN7hv1COzWBtb5fdGg6ecOOTzrFpNgCgg1M5Ohh7JoSVPj4oTCdapumMybQ2kaUPrxfTkRrFxJKGOVbZritltceASyprZTjE5ehoy2kkoJ8ozOjoCznxR1Bb_lsmkDlruLRzrMPpePFB0WzKNWTMJqdaJ6GFxamRr7BAWrq81MXscljuB3UZcYKGi7DiWvqdApnj7haPccVj6u9d1IbVJy1BuBzIo_fx0go.Fqj4E3Fytw2aVfc5CWRa._49vt5WuWOmJC7nC2Qyb0JPlRasPOOnEnxY3WSSkLMXx56F1U0bPopsZjk8EFMP.WRzbv8PDy.AdxPf0JdI9Vgz0rsgb6RFsMZNtmFZDKHxBAckK0biU1lFmAfDjdlFX6G4tQp7gKCkMPKwsv2uNPXcGg7i7y04ni9LQu7J098QvRNiEq2iGPoaQv2oersMGwT4H4.Ecx04R6aT051xc1xZSg9n1gtbHfrbTw5eZS_wfxZYiC_caJ5L3F_8.9VAClQSF63cC_UfKa4nitO1BOLBSPObkpcs37hu0bVVMGf6KM.9FMLfEHl17mG5xr.zGrsk6QGO6hkSS5kFVo7nzCFXubrxqJVD_Pdr2vT.0HNE63Z9rszKW_GgVjZYyYmu0U7c8hh5xOj6DGTrDagm0azz6RzLXwzdXuG_t._ZsRDUZnyKOKkUSsQlMVp7pV5ZTTO7FN18GoGeqDbngQHX.j2SVMLJllT4osDSUVPdSDOLj5j7smnlhgx0QHd0at52VdrLfl5Gw0JM_XwrNxNctUbhiSio_m6C4KGl413iHBZdYIhyZwK91Vnbop_w5N7WVE8ilWt8QkG8RzhdmZZjrf6X1CJ21MaImXOnbGmmRYd2X7kJhAfJBU7qRsz8Kpe9EHuPo7z6hh1bY1bj63w95f9.2ISpjh_m56lvTZgRdaSLaamRDF96m9ttMrdGeeGcsL0F3asUkvUufi_oYSXxoI2Hvc22D3k7_kRt2RzwMne1Rp0_fo_Aifr5wcUIoqcLjSayFDquMlsCPhthEmsIAUbVek7.BTx6RYQPsYrnOOJaeHAH.Z_8IQMpLK6bTGjJKkqVt1jkJYM_wi7fkp79cX1_m7uKMKx5pDlcC_w8oy1ZQYHmBpv2oaazCqQGZSfYHMr33TaH9JT9ZJcTpxOo6KbGqq0cMmtqHsF_5WdxAnScQbLvUbuV7sofKGEjjfUEr.6SZ5sVaQt5KQgQGUN6FsaM00Ayf1Gm7ZWmjVtBny7uL.MotRH8b_X3h5hSqtZwaiMv2rjrKBVnKjNUbTYGsPCZrPepvSYVMVXiidh8Bblm65SePZc3YUZab6INVfpzCH6Z9Rxfu1AmdVSLQaX77.uedQr0Isq0E5R4oAWYywfYZyYq36QI1AuCGmTEwZaNK.QW1YyH1Grm5WEke80zhyMLV2r4q4BsY3a4Smw1t4rRLk4o8Pds9EleDU505aklkqSUm2FwM29FpZvzFT1KiZcZ4lZAt25LcG0XERXz2mNKvhErI7t08QehyJlu19jzi99wBKOGJ1FdwQley3Tg3fq5pEsTgnuCciCums2JzPYSI5thfIDRUYXFCYgJ4ROEMtmvB2ZSpllQcNOql9GZ5yinwbE6mJK81tApynr8jmWMMV.I8LlyVWamWPuARNab96wttQAQ01FAKSCLIfDQN3zKxOr._bevQL9ybUdmwBy0tTo6qGi4c3nftYkZXODH7pjJHfUNszoeBBJU6bz324JC3S2l_qGnsJXkVWoei5XfxX25uogYFiSOneNylC_RZvoT1FkMKv0TUn.A38QDaK6MrE8L_aKta3CNaGQHz90kZosg_mu3QazsucVS6zZQrDvTORs1kGDPhLvFM8Gq_o2Vs3WoVF.HCImvXUS"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=921139845fa1fd71';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, "\/solutions\/?__cf_chl_rt_tk=6_2LRzyOTl_KJQzxA_WKNQGT.NxHYkPNV7wm6qjwuv4-1742096379-1.0.1.1-tJA.Xe5asOwK9Z5DZT_BOL0u4NN4sfuyYuKbqhP_cg4" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>