easy

#include<iostream>
#include<string>
using namespace std;
string number_code = "1234567890",s;
bool in_code(char c)
{
    if(number_code.find(c) != string::npos){return true;}
    else{return false;}
}
int main()
{
    int sum = 0;
    getline(cin,s);
    for(int i = 0;i < s.size();i++){if(in_code(s[i])){sum++;}}
    cout << sum;
    return 0;
}