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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n;
    cin >> n;
    string s;
    cin >> s;
    string num = "0123456789";
    string lo = "abcdefghijklmnopqrstuvwxyz";
    string up = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string sp = "!@#$%^&*()-+";
    
    int cn = 0, ca = 0, cA = 0, cs = 0;
    for (char ch : s) {
        cn += num.find(ch) != string::npos;
        ca += lo.find(ch) != string::npos;
        cA += up.find(ch) != string::npos;
        cs += sp.find(ch) != string::npos;
    }
    cout << max(6 - n, 4 - (cn > 0) - (ca > 0) - (cA > 0) - (cs > 0)) << endl;
    return 0;
}