Hamming distance

#include <iostream>

using namespace std;

size_t dist(const string& a, const string& b)
{
    size_t k = 0;
    for (size_t i = 0; i < a.length(); ++i)
        if (a[i] != b[i]) ++k;

    return k;
}

int main()
{
    string a, b;
    cin >> a >> b;

    cout << "Hamming distance: " << dist(a, b) << endl;

    return 0;
}