#include <iostream>
using namespace std;
int main()
{
    // 请在此输入您的代码
    string a;
    int f = 1, count;
    cin >> a;
    for (int i = 0; a[i]; i++) {
        if (a[i] == a[i + 1]) {
            f = 0; count = 1;
            for (i; a[i] == a[i + 1]; i++)
                count += 1;
            cout << a[i] << count;
        }
        if (count == 1)
            cout << a[i];
    }
    if (f)
        cout << "NO" << endl;
    return 0;
}