#include <iostream>
#include <string>

using namespace std;
// isdigit判断字符是否为数字字符
int main(){
    int count = 0;
    string s;
    getline(cin,s);
    for (char c: s){
        if (isdigit(c)) count ++;
    }
    cout <<count;
    return 0;
}
// 枚举判断字符是否为数字字符
int main(){
    int count = 0;
    string s;
    getline(cin,s);
    for (int i = 0;i < s.size();i++){
        if (s[i] >= '0' && s[i] <= '9') 
            count++;
    }
    cout << count ;
    return 0;
}