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: "catalog.aap.org",cType: 'managed',cRay: '8e71341f594c3e4f',cH: 'p5HnrHN1WY_eK9mFdJtvuZGpHxtsoDIG1d2lWT4svcc-1732365373-1.2.1.1-RA97U_ZeRuQzIXIJAG3GhpGMWSb56KHK7e6s22sy.ANh9MGOuz7hOK9RtJQodQHy',cUPMDTk: "\/?__cf_chl_tk=Q2xd1dFCj3RJIrC7LJPG52CdmQNTIxnNVbnxGAMrqBQ-1732365373-1.0.1.1-UPNBS.lcMwledmccej8K2SeShub_2JiYIu.Fs0TDnyw",cFPWv: 'g',cITimeS: '1732365373',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/?__cf_chl_f_tk=Q2xd1dFCj3RJIrC7LJPG52CdmQNTIxnNVbnxGAMrqBQ-1732365373-1.0.1.1-UPNBS.lcMwledmccej8K2SeShub_2JiYIu.Fs0TDnyw",md: "f0Bn5qKfQBMYT9kfehinv7x9Jr_gY_MoTXM2.VTu4Kc-1732365373-1.2.1.1-OLiYlxkSmNylEVxuew8WRXzeRypOHOb3OJVg6_qLaIjxztlIZUT3bWllSnvl7R2_D.nhLkiwp_IktLhR5ZZsHKZi0gb429pIbl4TFbKoYy7GWsEda1j8o_1vwp2bjrvh6P69hnGjkowUcgy3sbq74dVwU.9FDNRLkD6KGPLivbS4B1osHB0YMCEjTVFTlwE0Kffb0so_tpblQeFs0iQjUOLKu3uHjLFh2hUjZz8H9Y2OgcE0dpZZNm7W95sDUL8z3eaA.VY3XfH3S3N4FvLnkdfv17KNugzVkzfFzsSYVvMfk07TXZDo5ebwuiw3pRj6cTf3tdtO4bWcEYeqPBtd7n9MU1AeT9Yo9GdKCLvamhgL92Y6YxE1aDBDt48FxxUMMRFPHzzECCprCUNgyvbijQP1OOpmsAjXuQqxKKg.66Xo9hUMe9NdNbvmWUqkbkKk6VL1_keUrkic_dI85h6Roe9jRUCKRGMOF_TEjfSNNMxrEf5GoqSVN5CtFYUqt194ZadYOz9B4_J.i.Fr3v6gxbne7GzcvWSMp4S7ocKcKVYM_tjjt2efbs_bLmZ6q__B48EBYMaDRNYGECZO6lyMy3UDf.7pftGB4jWjsasg1e3teYhatJ5uxAg.W3t7HfIQw7UloT9S1mFeFKITY44ssHmBb.x8kyL69BJ8Hr6d6PrecQ6HsKiTDwRbPG..o4gBxp__n0kBReG.RDLt1IqWegXC3M1YIbNEoOvHnBMvSqSnZ7SqO07C1.7lmMgTC3aNMcP0MWZ0OHW.CA0TC8vQThs_.Ie9WOJ70M73zIeOPUWoQhDv9M41Y7aDZml2ji3lSbMxYIMRLRDfOPYYYdoi9QWUFAmueTUqxEFuFWCp64RtZ89ly42RGd4aJXSHJ6HG8.Ew0_5chHXzotlSn0wmoKey.8G78o3D5c0J2gQ3SK7ZfYs1BHjej9GG67TKoHjcOQEPfrlh20KWZtnJvmw_WPxDzUPmsajK6TPqaryFfZ54r01ZGmQgFeL9S0jkqOFcGoq0KsZVBc5BS4bw6.eURQA9SK7UOEsRCDDYO5rMDHjLcaXkqkM8WDuwDGZq.X4IGxuJ7zV7KyBjSKeTu3ApvrLW5mHaUg0lXThNCLY.txZCr0JRLDBbVu0l1MHfouyO6.GtgN7mqFC8A.CUm3AFkLEPxMtYupuSy8XyCrK4Rm946UteuFkk0IQL7IWM6HOsFqiqYMyyPEvrVdT31q68_daG_jtnPCbOSFzpjJeRq8y90aYOOpFOiGo9sdYrLI76WRogzyOhTm089iBrDPDEWJ6vssc_93dozZu99JEKNpSk.7kgBZiSdMOY19s5cjnp7CmEPnsHomTwYzew.wAJcMtLMU3uZ3fR1VZBPlMYHYX8l6QSFErJGhV1h9v.o5indD2p.gX3ccl0M7pYk5lqTwrl9rgF0SuGRIzUL8SwlSFgiJhGKLPePUyX0msSjQLRSj1MtyPpJ14YIy2Gg3fswQ.Jr19F5hXyiWLxX06SjY4hoEAOvUPzTQOUZG7yxIGlVcYe3ZsuDdwJcTymKKP8xE5bQDbx7h7P4.OcomLQ.ygk37fg9ilrYNg_WP9ugxGNblUGg0JZmte7Kr14HxasaNm3.ZGtGmo_W_IEUuZj_LKjMjG.lliS2TQX0kM4EbEmg..q9n758sqGDkY596gvGGWAr8jtEDgxvt.aBB.6blfgmNfHp0B.uhn7Qg656_3jmZy1g7oD0a007LKafIK3uK6dxjpMfl6qKeTi6UrPmg3ibZNtY5ZT0QRPnp4v4v7R0A8.TA7D578QE9VgI2sMc2WXvrewtdUTSou94pmcYHqKQ0HUzeW1V21uXmNyi05H1ZNC9lscsVuFIDfKvh392HAp3aJBBglgIYS68iCeDUsTjAvb7w4bnTVBBqNPYa_LFvdB5WXEClx99IxIbIUjzy8EfmqoD1e1MXpUlIsdbTjSb5YY0TEIAeYp0NJ0HZcVaInS3opZ0pDrX0kexraJNLvCnWZvCE5c_PCCwb1rhHMxN8asrn8WUnn.BMN8EBIt6pCl2XAUtGjfYiRgcYTJ96ouY_KQz9rBPvBIdI7AFZkdV8yYUyFLq5FCu3vNuJmGJchvWI0VctgDa2fQjU.HmfGSP5cWS6WycYRraI57hoF4k20a7U_4aeBDO9EcoOL3g8w48LAhg_.9XeqvkKIPjBR3UoNDXaIJWufb1qZi74Qj9PbRGLtGpAu22MTF1eUxstxtRh6D.B2jXOvitTZJmayeo.jvgfb2Iu2hXMuHmwht04rWoX.xqUwOF8YFm7LqOpCcYD0J4jxkFKGULetcWCH55S5vywAR.hpBKSiJDFEBIieSEZQTU7kgNgq5UkGokGB4T5I4hMkofJpKM6XfN_8o4JbVIbU5Q6QuvFL3Qd8_ZozpRI2uosXNb5fF.6QWH_Q9ehTS5wZzKXASECtE8oe7ty60KFHi9RdmEj2EwrV6W5jpiBOJQ06WcbeMin5WjpgJpU5G3xTISNFbh7Ib5m4L8qMEbwh2T_dIvDvWJX5b96nyNSdEWrn3JyC89Q.YFufIm4OSkfMnKUC2MAD37ndxhsmYc1SEOogcJGGgoe8fNYtWCJfyOnMdH3ppHwgCrGKlIMgS3RsSImg4ROsQNe2aWcst7IjW9rz5YFTu6jQIRu7YZKEbWK_N529COq.K48e.QRO6sD8ZeATJM0Qk7IlhiJYUKT0EVh_rtAE8ZxOi7fP4eTeRqhId5lVboH0y_EKXjdY5SLUJWpJ23pr2YBRU1P9F262Nse0DwpC5RxZO3_Tn1jZsvB_nGji_xFkwiWJAYhv.pGII_QUDEFao6U9LUXlJF1X0dm9FbEVvPLZ0HiVrZ0oB2EYOVzxnk8yr",mdrd: "zXicuRQycEGg79kxaJsOa0L2iQmjZNtAOVeSBp2p3w0-1732365373-1.2.1.1-yr3Fe0HolcE.UkEMaF0AiyybbZ06bihVNWdbx.yReKTXnDUWB1uu88h0vIJk33tcYIpB76QLH2I4i_WQOeICdqwv3U5RYpG3WQVyVCc6a_w6OjpAbRQ9E1W1d7ng3mVhHrOfrCA4eTqr_1TcWLN7gN_UWor_t0CFgDNG9kfNgyRqv0CjLtr.sfaIyurwCw8W_CtNRjdLB7dE_9cuphqq7n2VHdCKDsbHvXi1TrZoTagu_W1fZqdQ9MAkowHSWJ0OIvdGMmIWrcRdCWcYtTSleDJE0gN9ip27m6qZiXQt39XDSUM_H0GEUOsM4AE7N9G6M1nAQMgelH9g_p8zgwVpoq.2RkSznQtEKSD4F5eSmkceMGj6kmrn_vac01yz01A8tPW8P9TRPGI1BFpLy2qSL5cSwR5k2gVr_xlxHRRhYnSm1zNURBoni0YkDzRtelq7uOyzM7bLsAnEvrdtHmZWJvyyXtGFCvtVNtBOsF6r.w7dLZ4rDMIo9OoZ1y6.9N0XhYk5zPD2Z13EorIKEpBfA__5RtcKfRjZ7jzoOTJb3stE45KvnvesJmv9DYEwjXbw_ogkfks0plpkLIiytzH.97UFFg8zqnD2QexR9VzKn6wACPzUe7ISeHaPzQYmoV1wzblChi_QAHzF0gYrhjN4G24W8Rpgufcjxpz0HwRRiP8lcAFQVng7natRqQZ7YhAF40cVr2CZSwuX5CFOhWUGOQio48jppIN9ddIsLYZlJ2eGY43IZx3dl4mrFZjpMd8xcP49B5acI_wsjPirGB.7N28EK1ojMRO6vp13XhjwLT95Ajnkbsg_tjdFCzuZkr2KNJSSpbDMSVm9Lge8KuuydyaCgi14TipIO6WalGQgfh6mRSNsTTO0u.6nZDmgPvNhTMtoxQOQ9quPv9lGuvZVCWkQtAakqf6VjvAX7.Gt3_Ko9IjZG8UcuRqt7nKqcTy8CDjEigC_g2z1gRIc4s75z8yza79a8SEghyJ2BRbm653XDtdGiKIm_anYpT6xsPWf52p9lw.8ltzgGrYTtkdNF9apKtqKd_0EZ4RtTluwXke6EOuk5NJMD4dEOUvaSk4hvWOWGMpRQfvrNpnY724jOb4HKBF1zO11Y0JyTZAztz248JDdQY5uPPe2QTsZs.2mU4TDSjazHAPJk8QBK62WuvXDnEfgbhG3ANLeqURNARguCaqeODcSFf_.kh13oi03Apyn9FPOXf6HF_rO_k_U.8BfMxZuUMR7XKY6cnElJ9nLjYsCwPpxUahQ6AB3CpYpk9cPjnfog9N6tHwSlkv1o62IQ9YOO2BTusNDejWg2HmmZfZai7aeUm4oia1962mBrqFub0gGaAsSmK1vD1c846pkBpQAoKXTETET6ULhQpD2YtCf_ROA0FiS2vV4Q1P0J0G0.zCeeP9HkpMRRC3p0neMalj5du9E6OlorIbsIwSsAbNezZ76mSZxIy0oW1oi_aaoCdck9j1FKier9ONM0dqr_M0qGU8xZpi7X7LMxeExo.oVFSeV_1EBUmMYg2AsWpQFwMIM6HKh_8DTPvRV_OhAViKMPV8MRokNHpGKZTZB4b4UOYsbfME.7Kp2Ye347vhT4yoKVMd98aikHBke7vkB7FfhUZ2sCgwiFQVFqYL_r8ZZJ8eMU_62CIJInC3Fko0fDRY1gE5N5PfQatj07JN8xeDB3Zt1YpOmZrkr1_B6nNVAcZPx9eR_AP_QZ6TzCm8V2Tbg3wPPOtoEzl8pP1mK6tiJVPQVnjt46UqiaOZDN9fpzHO1NVxuPZZ_01nxhpxZEdNZgDTqn0hfqAeUnYBXNcznQtjxuVXRXs_Kyhv8HjNMjac.LiVIkDnOuQKSoOm585TVVk7y891czBbGsLDoVFBIC1qD.SAw1sBTLbOuddpq0bwctXnww2j7b74u0ntrpKNUI7lWa.ZRY3t5xgLxxyMFwM0VZQAxHbqhQrJLdipc2nR_FV9RcauijIY9"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=8e71341f594c3e4f';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, "\/?__cf_chl_rt_tk=Q2xd1dFCj3RJIrC7LJPG52CdmQNTIxnNVbnxGAMrqBQ-1732365373-1.0.1.1-UPNBS.lcMwledmccej8K2SeShub_2JiYIu.Fs0TDnyw" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>