/in/foo.cc:6:28: warning: 'ans' defined but not used [-Wunused-variable]
  static int prime[S],sum=0,ans=0;
                            ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:33:14: warning: iteration 31998 invokes undefined behavior [-Waggressive-loop-optimizations]
    if (!jud[i]) 
         ~~~~~^
/in/foo.cc:31:17: note: within this loop
   for (int i=2;i<=n;i++)
                ~^~~