#include <iostream>
#include <cstring>
using namespace std;
int main(){
char cs[300];
cin.getline(cs,300);
int len = strlen(cs);
int sum = 0;
for(int i=0;i<len;i++)
if(cs[i]>='0' && cs[i]<='9')
sum = sum + 1;
cout << sum << endl;
return 0;
}