#include <bits/stdc++.h>

using namespace std;

int findstr(string str,char c)
{
    for(int i=0;i<str.length();i++)
    {
        if(str[i]==c)
            return 1;
    }
    return 0;
}

int minimumNumber(int n, string pass) {
    // Return the minimum number of characters to make the password strong
    string numbers = "0123456789";
    string lower_case = "abcdefghijklmnopqrstuvwxyz";
    string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string special_characters = "!@#$%^&*()-+";
    int num=0,lc=0,uc=0,spc=0;
    for(int i=0;i<n;i++)
    {
        if(findstr(numbers,pass[i])==1)
        {
            num++;
        }
        if(findstr(lower_case,pass[i])==1)
        {
            lc++;
        }
        if(findstr(upper_case,pass[i])==1)
        {
            uc++;
            
        }
        if(findstr(special_characters,pass[i])==1)
        {
            spc++;
            
        }
    }
    int len=n;
    len = len + (num==0) + (lc==0) + (uc==0) + (spc==0);
    if(len<6)
        len=6;
    return (len-n);
}

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