Result

AC

Code [DL]

console.log(require('fs').readFileSync(0,'utf8').split("\n").map(q=>{a=parseInt(q,2);for(i=1;a>0;i++)a-=i;return a==0?1:0}).splice(0,50).join(""))

stdin

00010101
11100111
11100001
00011000
10111100
00110001
01101101
11011011
00100111
01001110
00011100
00101101
01111000
01011100
00001111
10011100
11010010
00110010
01010100
01001110
11000011
10001001
00100100
11001100
11010100
10001000
01000010
00001010
00000001
10110101
00011101
01011101
01101001
10111110
01011011
01100001
00111110
00000110
00000000
00110111
11111101
00011110
10101011
11101010
00000011
10111111
10011001
10010111
01101001
11011100

stdout

11000000011110101001001001111000111001111010101010

stderr

strace