#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string s) {
    int fl[4];
    for(int i = 0; i < 4; ++i) fl[i] = 1;
    for(int i = 0; i < n; ++i) {
        string spec = "!@#$%^&*()-+";
        if(s[i] >= 'a' && s[i] <= 'z') fl[0] = 0;
        if(s[i] >= 'A' && s[i] <= 'Z') fl[1] = 0;
        if(s[i] >= '0' && s[i] <= '9') fl[2] = 0;
        for(char ch : spec) {
            if(ch == s[i]) {
                fl[3] = 0;
            }
        }
    }
    return max(fl[0]+fl[1] + fl[2] + fl[3], max(0, 6 -n));
}

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