Compilare: user.cpp: In function ‘int main()’: user.cpp:31:15: warning: unused variable ‘phi’ [-Wunused-variable] long long phi = N-1; ^ user.cpp:24:42: 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:25:46: 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:27:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &A); ^ user.cpp:28:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &N); ^ user.cpp: In function ‘long long int exp(long long int, long long int)’: user.cpp:18:12: warning: ‘sol’ may be used uninitialized in this function [-Wmaybe-uninitialized] return sol; ^