The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1
 0  7  0  0  7  7 28 14 21  0  7 21
 0  0  7  0 35 28 21 35 42 21 21  0
 0  0  0  7 35  7 14 42 42 28  7  7

generates a code of length 12 over Z49 who´s minimum homogenous weight is 56.

Homogenous weight enumerator: w(x)=1x^0+222x^56+432x^63+540x^70+14406x^72+840x^77+366x^84

The gray image is a code over GF(7) with n=84, k=5 and d=56.
This code was found by Heurico 1.16 in 0.0331 seconds.