最后五个

#include <iostream>

using namespace std;

int main(){
    string s;
    cin >> s;
    
    int sum = 0;
    for(int i =0;i < s.length();i++){
        if(s[i] >= 'a' && s[i] <= 'z' || s[i] >= 'A' && s[i] <= 'Z' || s[i] >= '0' && s[i] <= '9'){
            sum++;
        }
    }
    cout << sum;
	return 0;
}