Binary (68,4)-code with minimal distance 36 

[10001111111111111111111111111111111111000000000000000000000000000001]
[01001111111111111111100000000000000000111111111111111110000000000001]
[00101111111110000000011111111000000000111111110000000001111111110001]
[00011111000001111000011110000111110000111100001111100001111100001111]