#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

char s[110];

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

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n;
    cin >> n;
    scanf("%s", s);
    int num = 0, spl = 0, lc = 0, uc = 0;
    for (int i = 0 ; i < n ; ++i) {
        if ('0' <= s[i] && s[i] <= '9') num = true;
        if (specl(s[i])) spl = true;
        if (s[i] <= 'z' && s[i] >= 'a') lc = true;
        if (s[i] <= 'Z' && s[i] >= 'A') uc = true;
    }
    
    int def = (num ^ 1) + (spl ^ 1) + (lc ^ 1) + (uc ^ 1);
    cout << max(6 - n, def)<< endl;
    
    return 0;
}