The generator matrix

 1  0  0  1  1  1  1  1  1  1  1  1  1  1  5  1 15 10  1  1  1  1  1  1  1  1  1  1  1 20  1  1  1  1  1  1  1  1  1  1  1  1  1 15  1  1  1  1  5  1  1  1  1  1  0  1 20  1  1  1  1  1  1  1  1  1  0  1  1  1  1  1  1 10  1  0  1  1  1  5  1
 0  1  0 15 10  5  1 22  8 16 11 21 14  7  1 12  1  1 18 11  9  3  4 17 13  0 24  2 13  1  6 23 17 10 12  8 24 14  2 16  1 19  5  1 11 18  4 10  1 15  2 16 17 15 20 24  1  0 24 21 19 18  1 14  7 13  1  2  5 21  1  4 23  1 13  1 10 14  4  1  6
 0  0  1 16  7 24  4 14 19 22  8  5 12 17 23 15  2  9 23  6 20 10 21 18 11  3  4  6  7 16 17 21 19 12 16  2 13  9  2 23 10  2  1 11  9 24  0 18  8 24  5 11 13  0  1  3 10  7 16 19 21 21  6 10 24 20 10 10  2 22 14 23  8 20  8  3  3 22 14 19 16

generates a code of length 81 over Z25 who´s minimum homogenous weight is 312.

Homogenous weight enumerator: w(x)=1x^0+380x^312+380x^313+400x^314+524x^315+860x^316+1160x^317+980x^318+800x^319+564x^320+920x^321+1000x^322+860x^323+380x^324+296x^325+420x^326+840x^327+400x^328+500x^329+340x^330+380x^331+540x^332+600x^333+160x^334+288x^335+200x^336+520x^337+280x^338+260x^339+112x^340+220x^341+60x^342

The gray image is a code over GF(5) with n=405, k=6 and d=312.
This code was found by Heurico 1.16 in 0.542 seconds.