/in/foo.cc: In function 'int main()':
/in/foo.cc:45:9: error: 'cin' was not declared in this scope
         cin>>a>>b;
         ^~~
/in/foo.cc:55:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for(int i=1;i<=cur;i++)
     ^~~
/in/foo.cc:57:2: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
  printf("%d\n",ans);
  ^~~~~~