/in/foo.cc: In function 'int main()':
/in/foo.cc:61:30: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for (int i=2;i<=N+1;i++) for (int j=i+1;j<=N+1;j++)
                              ^~~
/in/foo.cc:64:2: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
  printf("%d\n",ans);
  ^~~~~~