Compilare: main.cpp: In function 'int main()': main.cpp:99:32: warning: array subscript 3 is above array bounds of 'long long int [3][3]' [-Warray-bounds] 99 | sum = (sum + (a.m[3][i]*v[i])%MOD)%MOD; | ~~~~~^ main.cpp:9:15: note: while referencing 'Mat::m' 9 | long long m[3][3]; | ^ main.cpp:93:13: note: defined here 'a' 93 | Mat a = fastexp(init,n - k - 2); | ^