Wrong Problem!

I was solving the problem of Adding Reverse Numbers in nogoctuan_contests but when I submit I get an error named “Wrong Problem!”. I don’t know why it is happening.
If by any chance it is due to my code(which, most probably, is not the reason here), do have a look on my code:

//Problem from SPOJ contest
// Adding reverse numbers

#include <iostream>
#include <string>
#include <stack>
#include <algorithm>
#include <sstream>

using namespace std;
string removezeroes(string str) {
    int i = 0;
    while(str[i] == '0') {
        i++;
    }

    str.erase(0, i);
    return str;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    //my code
    stack <int> s;
    long a;
    ostringstream strval;
    string x, y;
    long m, n, val;
    cin >> a;
    while (a--) {
        cin >> x >> y;
        reverse(x.begin(), x.end());
        reverse(y.begin(), y.end());

        m = stoi(x);
        n = stoi(y);

        val = m + n;
        
        //string stri = boost::lexical_cast<string>(val);
        strval << val;
        string newstr = strval.str();
        reverse(newstr.begin(), newstr.end());

        
        cout << removezeroes(newstr) << "\n";

        strval.str("");
        strval.clear();
    }
    return 0;
}```