Compilare: user.cpp: In function ‘int main()’: user.cpp:55:17: warning: unused variable ‘j’ [-Wunused-variable] long long i,j=0; ^ user.cpp:53:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cumpanit.in","r",stdin); ^ user.cpp:54:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cumpanit.out","w",stdout); ^ user.cpp:56:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld",&a,&b); ^