#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string p) {
    // Return the minimum number of characters to make the password strong
    int count = 0;
    bool f1 = false, f2 = false, f3 = false, f4 = false;
    for (int i = 0; i < n; ++i) {
    	if(isupper(p[i])) {
    		f1 = true;
    	}
    	if(islower(p[i])) {
    		f2 = true;
    	}
    	if(isdigit(p[i])) {
    		f3 = true;
    	}
    	if(p[i] == '!' || p[i] == '@' || p[i] == '#' || p[i] == '$' || p[i] == '%' || p[i] == '^' || p[i] == '&' || p[i] == '*' || p[i] == '(' || p[i] == ')' || p[i] == '-' || p[i] == '+') {
    		f4 = true;
    	}
    	if (f1 && f2 && f3 && f4) {
    		break;
    	}
    }
    if (!f1) ++count;
    if (!f2) ++count;
    if (!f3) ++count;
    if (!f4) ++count;
    if (count + n < 6) count += (6 - count - n);
    return count;
}

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