Problem: different letters parity

Code: different+letters+parity/tails_1642076932

Nibbles version: 0.2 | 0.21 | 0.22 | 0.23 | 0.24 | 0.25 | 1.00

Format: Compact | Simple | +Type | Table | JSON | .nbl (DeBruijn) | .nbl (names)

% (modulus) 
    , (length) 
        `$ (uniq) 
            @ (= fstLine) 
    ~ (auto = 2)