#include <iostream>

using namespace std;

int main()
{
    char s[110];
    fgets(s, 110, stdin);
    int len = 0;
    for (int i = 0; s[i]; i ++ ) 
    if (s[i] >= '0' && s[i] <= '9') len ++ ;

    cout << len << endl;

    return 0;
}