cin.getline()
#include<iostream>
using namespace std;
int main()
{
char a[105];
cin.getline(a,105);
int num = 0;
for(int i = 0;a[i] && a[i] != '\n';i++)
if(a[i] >= '0' && a[i] <= '9')
num ++;
cout << num << endl;
return 0;
}