/in/foo.cc: In function 'int main()':
/in/foo.cc:24:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for (int i=0;i<1<<n;i++)
  ^~~
/in/foo.cc:32:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
   if (ans!=-1) cout<<ans<<endl;
   ^~