Untitled

#include <bits/stdc++.h>
#include <string>
using namespace std;

string add(string &num1, string &num2)
{
    string result = "";
    int carry = 0;
    while (num1.length() < num2.length())
        num1.insert(0, "0");

    while (num2.length() < num1.length())
        num2.insert(0, "0");

    int len1 = num1.length();
    int len2 = num2.length();

    for (int i = len1 - 1; i >= 0; i--)
    {
        int digit1 = num1[i] - '0';
        int digit2 = num2[i] - '0';

        int sum = digit1 + digit2 + carry;

        carry = sum / 10;

        result.insert(result.begin(), (sum % 10) + '0');
    }

    if (carry > 0)
        result.insert(result.begin(), carry + '0');

    return result;
}

int main()
{
    string num1, num2;
    cin >> num1 >> num2;
    string sum = add(num1, num2);
    cout << "Sum: " << sum << endl;

    return 0;
}