/in/foo.cc: In function 'void Euler(std::vector<bool>&, std::vector<long long int>&, ll)':
/in/foo.cc:13:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0;j<prime.size()&&i*prime[j]<=n;j++)
                     ~^~~~~~~~~~~~~
/in/foo.cc: In function 'll f(ll)':
/in/foo.cc:27:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<prime.size()&&x!=1;i++)
                 ~^~~~~~~~~~~~~