#include <iostream>

using namespace std;

long long N,nr,last,total;

int main()
{
    total = 7;
    cin >> N;

    last = N % 10;
    N /= 10;

    while (N != 7)
    {
        int cifra = N % 10;
        if (cifra == last)
            total--;
        last = cifra;
        N /= 10;
    }

    cout << total*9 + 10;

    return 0;
}