#include <iostream>
using namespace std;

int main() {
    string n;
    cin >> n;
    for(int i = 0; i < n.size(); i++) {
        char c = n[i];
        int brojac = 0;
        while(i < n.size() and c == n[i]) {
            i++;
            brojac++;
        }
        i -= 1;
        cout << brojac << c;
    }
    return 0;
}