#include <bits/stdc++.h>

using namespace std;

int n, u1, u2, u3, ct, u4;
string s, ss = "!@#$%^&*()-+";

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n;
    cin >> s;
    for (int i = 0; i < s.size(); i++) {
        if (s[i] >= '0' && s[i] <= '9')
            u1 = 1;
        if (s[i] >= 'a' && s[i] <= 'z')
            u2 = 1;
        if (s[i] >= 'A' && s[i] <= 'Z') {
            u3 = 1;
        }
        for (int j = 0; j < ss.size(); j++) {
            if (s[i] == ss[j]) {
                u4 = 1;
            }
        }
    }
    if (!u1)
        ct++;
    if (!u2)
        ct++;
    if (!u3)
        ct++;
    if (!u4)
        ct++;
    if (s.size() >= 6)
        cout << ct;
    else {
        if (6 - (s.size()) < ct)
            cout << (6 - s.size()) + (ct - ((6 - s.size())));
        else
            cout << (6 - s.size());
    }
}