Compilare: main.cpp: In function 'int main()': main.cpp:22:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[1].size() ; ++i) Sol = (1LL * Sol * (m - i)) % MOD; ~~^~~~~~~~~~~~~ main.cpp:25:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 1; j < v[i].size() ; ++j) ~~^~~~~~~~~~~~~ main.cpp:10:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("colorare3.in", "r", stdin); ^ main.cpp:11:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("colorare3.out", "w", stdout); ^ main.cpp:13:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:16:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^