#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    string numbers = "0123456789";
    string lower_case = "abcdefghijklmnopqrstuvwxyz";
    string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string special_characters = "!@#$%^&*()-+";
    int flag1=0,flag2=0,flag3=0,flag4=0,flag5=0,count=0;
    if(n>=6)flag1=1;
    for(int i=0;i<password.length();i++){
        for(int j=0;j<numbers.length()&&flag2==0;j++){
            if(password[i]==numbers[j])
                flag2=1;
        }
        for(int j=0;j<lower_case.length()&&flag3==0;j++){
            if(password[i]==lower_case[j])
                flag3=1;
        }
        for(int j=0;j<upper_case.length()&&flag4==0;j++){
            if(password[i]==upper_case[j])
                flag4=1;
        }
        for(int j=0;j<special_characters.length()&&flag5==0;j++){
            if(password[i]==special_characters[j])
                flag5=1;
        }

    }
    if(flag2==0)count++;
    if(flag3==0)count++;
    if(flag4==0)count++;
    if(flag5==0)count++;
    if(n < 6 )return max(count,6-n);
    else return count;
}

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