Plus i couldnt find the option on that site of how to look at other successful submissions so as to learn from them

Hi. Sorry for this stupid question but is there something wrong with this code

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
   freopen(" addin.txt", "r", stdin);
   freopen("addout.txt", "w", stdout);
   long long int a,b;
  cin>>a>>b;
  cout<<a+b<<"\n";
   return 0;
}