#include <bits/stdc++.h>

using namespace std;
string numbers = "0123456789";
string lower_case = "abcdefghijklmnopqrstuvwxyz";
string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string special_characters = "!@#$%^&*()-+";


int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
    int cnt1,cnt2,cnt3,cnt4;
    cnt1=cnt2=cnt3=cnt4=0;
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<numbers.length();j++)
            if(password[i]==numbers[j])
                cnt1++;
        for(int j=0;j<lower_case.length();j++)
            if(password[i]==lower_case[j])
                cnt2++;
        for(int j=0;j<upper_case.length();j++)
            if(password[i]==upper_case[j])
                cnt3++;
        for(int j=0;j<special_characters.length();j++)
            if(password[i]==special_characters[j])
                cnt4++;
    }
    int cnt=0;
    if(cnt1==0)
        cnt++;
    if(cnt2==0)
        cnt++;
    if(cnt3==0)
        cnt++;
    if(cnt4==0)
        cnt++;
    n=n+cnt;
    if(n<6)
        cnt=cnt+6-n;
    return cnt;
}

int main() {
    int n;
    cin >> n;
    string password;
    cin >> password;
    int answer = minimumNumber(n, password);
    cout << answer << endl;
    return 0;
}