Compilare: user.cpp: In function ‘long long int prod(long long int, long long int)’: user.cpp:6:15: warning: unused variable ‘p’ [-Wunused-variable] long long p,s; ^ user.cpp: In function ‘int main()’: user.cpp:25:13: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] if(p&1!=0)R=prod(R,A)%mod; ^ user.cpp:19:40: 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); ^ user.cpp:20:42: 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); ^ user.cpp:21:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld %lld",&A,&p,&mod); ^