Compilare: user.cpp: In function ‘void GetPhi(int)’: user.cpp:37:9: warning: unused variable ‘nrPrimes’ [-Wunused-variable] int nrPrimes = primes.size(); ^~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:78:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &mod); ^