#include<iostream>
#include<cmath>
#include<cstdio>
#include<algorithm>
#include<cstring> 
using namespace std;
int main(){
	char a[260];
	cin.get(a,260); 
	int tmp = strlen(a),cnt=0;
	for(int i=0;i<tmp;i++){
		if(a[i] >='0'&&a[i]<='9'){
			cnt++;
		}
	}
	cout << cnt;
	return 0;
}