Binary (56,4)-code with minimal distance 29 

[10001111111111111111111111111111000000000000000000000000]
[01001111111111111100000000000000111111111111110000000000]
[00101111111000000011111110000000111111100000001111111000]
[00011110000111100011100001111000111000011110001111000111]