#include <iostream>
#include <cstring>
using namespace std;
const int MAX_SIZE = 100;

int numberOfDigits(char string[], int &counter, int size, int i)
{
    if (string[i] >= '0' && string[i] <= '9')
        counter++;

    if (i == size)
        return counter;

    i++;
    numberOfDigits(string, counter, size, i);

}

int main()
{
    int counter = 0;
    char string[MAX_SIZE];
    cout << "Enter the string: " << endl;
    cin >> string;
    int size = strlen(string);

    cout << numberOfDigits(string, counter, size, 0);

}