#include<bits/stdc++.h>
using namespace std;

int n;
string s;
int ans;
bool dig, lower, upper, special;
set<char> c;

int main() {
    cin >> n >> s;
    ans = max(0, 6-n);
    string t = "!@#$%^&*()-+";
    for (int i = 0; i < 12; i++)
        c.insert(t[i]);
    for (int i = 0; i < n; i++) {
        if (s[i] >= '0' && s[i] <= '9'){
            dig = true;
        }
        if (s[i] >= 'a' && s[i] <= 'z') {
            lower = true;
        }
        if (s[i] >= 'A' && s[i] <= 'Z') {
            upper = true;
        }
        if (c.find(s[i]) != c.end()) {
            special = true;
        }
    }
    ans = max(ans, (!dig) + (!lower) + (!upper) + (!special));
    cout << ans << endl;
    
    return 0;
}