Compilare: main.cpp: In function 'std::array<std::array<long long int, 50ul>, 50ul> operator*(std::array<std::array<long long int, 50ul>, 50ul>, std::array<std::array<long long int, 50ul>, 50ul>)': main.cpp:24:33: warning: value computed is not used [-Wunused-value] (c[i][j] += a[i][t]*b[t][j])%MOD; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~ main.cpp: In function 'int main()': main.cpp:42:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen(file".in","r",stdin); ^ main.cpp:43:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen(file".out","w",stdout); ^