c-gcc, 128 bytes

Result

WA

Code [DL]

int i,a,b;main(){for(;++a<50;){for(b=i=0;b<8;b++){i+=getchar()&1;i*=2;}getchar();i/=2;for(b=0;i>0;b++)i-=b;putchar(i<0?48:49);}}

stdin

10111110
11111101
00011100
11001001
00000001
11111000
00110111
01011011
01111111
10011001
11100111
10011001
01001110
00010000
00100100
01111101
11010111
10101011
10010100
00010101
01101000
10011010
00001010
00010001
01101001
01010101
00000110
00101101
10110010
00101011
10111100
01101010
11010010
10100010
10101001
01111000
00000011
10100111
10001111
01011010
01100101
00001111
01000010
00100001
10001000
00000000
01101110
01000010
10110111
00101110

stdout

1110101101111010010100101011000010011000011011010

stderr

/tmp/code.c:1:11: warning: return type defaults to ‘int’ [-Wimplicit-int]
 int i,a,b;main(){for(;++a<50;){for(b=i=0;b<8;b++){i+=getchar()&1;i*=2;}getchar();i/=2;for(b=0;i>0;b++)i-=b;putchar(i<0?48:49);}}
           ^
/tmp/code.c: In function ‘main’:
/tmp/code.c:1:54: warning: implicit declaration of function ‘getchar’ [-Wimplicit-function-declaration]
 int i,a,b;main(){for(;++a<50;){for(b=i=0;b<8;b++){i+=getchar()&1;i*=2;}getchar();i/=2;for(b=0;i>0;b++)i-=b;putchar(i<0?48:49);}}
                                                      ^
/tmp/code.c:1:108: warning: implicit declaration of function ‘putchar’ [-Wimplicit-function-declaration]
 int i,a,b;main(){for(;++a<50;){for(b=i=0;b<8;b++){i+=getchar()&1;i*=2;}getchar();i/=2;for(b=0;i>0;b++)i-=b;putchar(i<0?48:49);}}
                                                                                                            ^

strace