#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
bool f(string a, char b){
    for(int i=0;i<a.size();i++){
        if(a[i] == b) return true;
    }
    return false;
}
bool x(string a, string b){
    for(int i=0;i<b.size();i++){
        if(f(a,b[i])) return true;
    }
    return false;
}
int main() {
    string numbers = "0123456789", lower_case = "abcdefghijklmnopqrstuvwxyz", upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ", special_characters = "!@#$%^&*()-+";
    int n;
    cin>>n;
    string s;
    cin>>s;
    int ans = 0;
    if(!x(numbers,s))
        ans++;
    if(!x(lower_case,s))
        ans++;
    if(!x(upper_case,s))
        ans++;
    if(!x(special_characters,s))
        ans++;
    if(ans + n <= 6)
        ans = 6-n;
    cout<<ans<<endl;
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    return 0;
}