/in/foo.cc: In function 'int main()':
/in/foo.cc:14:41: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
  for (int i=1;i<=n;i++){scanf("%d",&a[i]);a[n+i]=a[i];}
                                         ^
/in/foo.cc:31:17: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
  printf("%d",ans);
                 ^