#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string str) 
{
    int l = str.size();
    int flag1=0, flag2=0,flag3=0,flag4=0,counte = 4;
    
    for(int i = 0; i < str.size(); i++)
    {//cout << counte << endl;
        if(!flag1 && str[i] >= '0' && str[i] <= '9')
        {
            flag1 = 1;
            counte--;
        }
        if(!flag2 && str[i] >= 'a' && str[i] <= 'z')
        {
            flag2 = 1;
            counte--;
        }
        if(!flag3 && str[i] >= 'A' && str[i] <= 'Z')
        {
            flag3 = 1;
            counte--;
        }
        if(!flag4 && (str[i] == '!' || str[i] ==  '@'|| str[i] == '#'||str[i] == '$'||str[i] == '%'|| str[i] == '^' || str[i] == '&' || str[i] ==  '*' || str[i] == '('|| str[i] == ')'|| str[i] == '-'|| str[i] == '+'))
        {
            flag4 = 1;
            counte--;
        }
    }
    //cout << counte <<'\n';
    if(str.size() < 6)
    {
        counte = max(6-l, counte);
    }
    //counte += max(0, 6-l);
    return counte;
}

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