#include <iostream>
using namespace std;

int main() {
    string s;
    cin >> s;
    for(int i = 0; i < s.size(); i++) {
        int j = i;
        int cnt = 0;
        while(s[j] == s[i]) {
            j++;
            cnt++;
        }
        cout << cnt << s[i];
        i = j - 1;
    }
    return 0;
}