Reverse two numbers and add then reverse the sum

Adding Reversed Numbers

#include <fstream>
#include <iostream>
#include <algorithm>
#include <sstream>
using namespace std;
//Reverse two numbers and add then reverse the sum.
int main()
{
    //ifstream cin("adding_reversed_numbers.txt");
    int n;
    cin>>n;
    for(int i=0;i<n;i++)
    {   
        int sum=0;
        int num;
        string s;
        stringstream ss; 
        for(int j=0;j<2;j++)
        {   
            cin>>num;
            ss.clear();
            ss<<num;
            ss>>s;
            reverse(s.begin(),s.end());
            istringstream iss(s);
            iss>>num;
            sum+=num;
        }   
        ss.clear();
        ss<<sum;
        ss>>s;
        reverse(s.begin(),s.end());
        istringstream iss(s);
        iss>>sum;
        cout<<sum<<endl;
    }   
    return 0;
}