#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    int n;
    cin >> n;
    string s;
    cin >> s;
    bool numCovered = false;
    bool lCaseCovered = false;
    bool uCaseCovered = false;
    bool sCharCovered = false;
    for(int i=0;i<s.size();i++){
        if(s[i]>='a'&&s[i]<='z'){
            lCaseCovered = true;
        }else if(s[i]>='A'&&s[i]<='Z'){
            uCaseCovered = true;
        }else if(s[i]>='0'&&s[i]<='9'){
            numCovered = true;
        }else{
            sCharCovered = true;
        }
    }
    int toAdd = 0;
    if(!numCovered) ++toAdd;
    if(!lCaseCovered) ++toAdd;
    if(!uCaseCovered) ++toAdd;
    if(!sCharCovered) ++toAdd;
    if(n+toAdd<6){
        cout << 6-n << endl;
    }else{
        cout << toAdd << endl;
    }
    return 0;
}