Compilare: user.cpp: In function ‘int main()’: user.cpp:6:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("modulo.in" , "r" , stdin); ^ user.cpp:7:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("modulo.out" , "w" , stdout); ^ user.cpp:9:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld%lld" , &a , &b , &c); ^