Compilare: main.cpp: In function 'int main()': main.cpp:31:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("classictask.in","r",stdin); ^ main.cpp:32:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("classictask.out","w",stdout); ^ main.cpp:34:37: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld%lld",&a,&b,&mod); ^