#include<iostream>
#include<cstring>

using namespace std;

int main()
{
    string s;
    getline(cin,s);

    int len = 0;
    for(int i = 0;s[i];i ++)
    {
        if(s[i] >= '0' && s[i] <= '9') 
        len ++;  //注意此处要加‘’，字符类型。若不加则0换为48，9换为57
    }
    cout << len << endl;

    return 0;
}