Compilare: user.cpp: In function ‘int main()’: user.cpp:35:8: warning: unused variable ‘d’ [-Wunused-variable] ll d = gcd(N, M, X, Y); ^ user.cpp:32:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("inversmodular.in","r",stdin); ^ user.cpp:33:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("inversmodular.out","w",stdout); ^ user.cpp:34:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld", &N, &M); ^