I got AC after several WA.
http://acm.uva.es/cgi-bin/OnlineJudge?AuthorInfo:53290
You're right this is a multiple input problem, also the precision is difficult to get right.
Personally, I implemented *exact* computation (which is possible because when you divide by 2 you always get a finite number of digits) to know where I got my errors. Of course I didn't submit that code because it would get time limit exceeded, but it helped me find my errors.
Here are 150 comma separated cases:
2^-8001 = 2.877E-2409, 2^-8002 = 1.439E-2409, 2^-8003 = 7.194E-2410, 2^-8004 = 3.597E-2410, 2^-8005 = 1.798E-2410, 2^-8006 = 8.992E-2411, 2^-8007 = 4.496E-2411, 2^-8008 = 2.248E-2411, 2^-8009 = 1.124E-2411, 2^-8010 = 5.620E-2412,
2^-8011 = 2.810E-2412, 2^-8012 = 1.405E-2412, 2^-8013 = 7.025E-2413, 2^-8014 = 3.512E-2413, 2^-8015 = 1.756E-2413, 2^-8016 = 8.781E-2414, 2^-8017 = 4.391E-2414, 2^-8018 = 2.195E-2414, 2^-8019 = 1.098E-2414, 2^-8020 = 5.488E-2415,
2^-8021 = 2.744E-2415, 2^-8022 = 1.372E-2415, 2^-8023 = 6.860E-2416, 2^-8024 = 3.430E-2416, 2^-8025 = 1.715E-2416, 2^-8026 = 8.575E-2417, 2^-8027 = 4.288E-2417, 2^-8028 = 2.144E-2417, 2^-8029 = 1.072E-2417, 2^-8030 = 5.360E-2418,
2^-8031 = 2.680E-2418, 2^-8032 = 1.340E-2418, 2^-8033 = 6.700E-2419, 2^-8034 = 3.350E-2419, 2^-8035 = 1.675E-2419, 2^-8036 = 8.374E-2420, 2^-8037 = 4.187E-2420, 2^-8038 = 2.094E-2420, 2^-8039 = 1.047E-2420, 2^-8040 = 5.234E-2421,
2^-8041 = 2.617E-2421, 2^-8042 = 1.309E-2421, 2^-8043 = 6.543E-2422, 2^-8044 = 3.271E-2422, 2^-8045 = 1.636E-2422, 2^-8046 = 8.178E-2423, 2^-8047 = 4.089E-2423, 2^-8048 = 2.045E-2423, 2^-8049 = 1.022E-2423, 2^-8050 = 5.111E-2424,
2^-8051 = 2.556E-2424, 2^-8052 = 1.278E-2424, 2^-8053 = 6.389E-2425, 2^-8054 = 3.195E-2425, 2^-8055 = 1.597E-2425, 2^-8056 = 7.986E-2426, 2^-8057 = 3.993E-2426, 2^-8058 = 1.997E-2426, 2^-8059 = 9.983E-2427, 2^-8060 = 4.992E-2427,
2^-8061 = 2.496E-2427, 2^-8062 = 1.248E-2427, 2^-8063 = 6.239E-2428, 2^-8064 = 3.120E-2428, 2^-8065 = 1.560E-2428, 2^-8066 = 7.799E-2429, 2^-8067 = 3.900E-2429, 2^-8068 = 1.950E-2429, 2^-8069 = 9.749E-2430, 2^-8070 = 4.875E-2430,
2^-8071 = 2.437E-2430, 2^-8072 = 1.219E-2430, 2^-8073 = 6.093E-2431, 2^-8074 = 3.047E-2431, 2^-8075 = 1.523E-2431, 2^-8076 = 7.616E-2432, 2^-8077 = 3.808E-2432, 2^-8078 = 1.904E-2432, 2^-8079 = 9.521E-2433, 2^-8080 = 4.760E-2433,
2^-8081 = 2.380E-2433, 2^-8082 = 1.190E-2433, 2^-8083 = 5.950E-2434, 2^-8084 = 2.975E-2434, 2^-8085 = 1.488E-2434, 2^-8086 = 7.438E-2435, 2^-8087 = 3.719E-2435, 2^-8088 = 1.859E-2435, 2^-8089 = 9.297E-2436, 2^-8090 = 4.649E-2436,
2^-8091 = 2.324E-2436, 2^-8092 = 1.162E-2436, 2^-8093 = 5.811E-2437, 2^-8094 = 2.905E-2437, 2^-8095 = 1.453E-2437, 2^-8096 = 7.264E-2438, 2^-8097 = 3.632E-2438, 2^-8098 = 1.816E-2438, 2^-8099 = 9.080E-2439, 2^-8100 = 4.540E-2439,
2^-8101 = 2.270E-2439, 2^-8102 = 1.135E-2439, 2^-8103 = 5.675E-2440, 2^-8104 = 2.837E-2440, 2^-8105 = 1.419E-2440, 2^-8106 = 7.093E-2441, 2^-8107 = 3.547E-2441, 2^-8108 = 1.773E-2441, 2^-8109 = 8.867E-2442, 2^-8110 = 4.433E-2442,
2^-8111 = 2.217E-2442, 2^-8112 = 1.108E-2442, 2^-8113 = 5.542E-2443, 2^-8114 = 2.771E-2443, 2^-8115 = 1.385E-2443, 2^-8116 = 6.927E-2444, 2^-8117 = 3.464E-2444, 2^-8118 = 1.732E-2444, 2^-8119 = 8.659E-2445, 2^-8120 = 4.329E-2445,
2^-8121 = 2.165E-2445, 2^-8122 = 1.082E-2445, 2^-8123 = 5.412E-2446, 2^-8124 = 2.706E-2446, 2^-8125 = 1.353E-2446, 2^-8126 = 6.765E-2447, 2^-8127 = 3.382E-2447, 2^-8128 = 1.691E-2447, 2^-8129 = 8.456E-2448, 2^-8130 = 4.228E-2448,
2^-8131 = 2.114E-2448, 2^-8132 = 1.057E-2448, 2^-8133 = 5.285E-2449, 2^-8134 = 2.643E-2449, 2^-8135 = 1.321E-2449, 2^-8136 = 6.606E-2450, 2^-8137 = 3.303E-2450, 2^-8138 = 1.652E-2450, 2^-8139 = 8.258E-2451, 2^-8140 = 4.129E-2451,
2^-8141 = 2.064E-2451, 2^-8142 = 1.032E-2451, 2^-8143 = 5.161E-2452, 2^-8144 = 2.581E-2452, 2^-8145 = 1.290E-2452, 2^-8146 = 6.451E-2453, 2^-8147 = 3.226E-2453, 2^-8148 = 1.613E-2453, 2^-8149 = 8.064E-2454, 2^-8150 = 4.032E-2454,