#include <bits/stdc++.h>
#include <cmath>

using namespace std;

bool isSpecialChar(char c) {
    // !@#$%^&*()-+
    return c == '!' || c == '@' || c == '#' || c == '$' || c == '%' ||
        c == '^' || c == '&' || c == '*' || c == '(' || c == ')' ||
        c == '-' || c == '+';
}

bool isDigit(char c) {
    return c >= '0' && c <= '9';
}

bool isLowerCase(char c) {
    return c >= 'a' && c <= 'z';
}

bool isUpperCase(char c) {
    return c >= 'A' && c <= 'Z';
}

int minimumNumber(int n, string password) {
    int oneDigit = 1, lowerCase = 1, upperCase = 1, specialChar = 1;
    
    for (char c : password) {
        if (isDigit(c)) {
            oneDigit = 0;
        }
        
        if (isLowerCase(c)) {
            lowerCase = 0;
        }
        
        if (isUpperCase(c)) {
            upperCase = 0;
        }
        
        if (isSpecialChar(c)) {
            specialChar = 0;
        }
    }
    
    return max(6 - (int)password.length(), oneDigit + lowerCase + upperCase + specialChar);
}

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