#include <bits/stdc++.h>
#include<ctype.h>
using namespace std;

int minimumNumber(int n, string password) {
    int l=password.length();
    int uc=0,lc=0,num=0,spl=0;
    for(int i=0;i<l;i++)
    {
        if(isupper(password[i])) uc++;
        else if(islower(password[i])) lc++;
        else if(isdigit(password[i])) num++;
        else spl++;
    }
    int req=0;
    if(uc==0) req++;
    if(lc==0) req++;
    if(num==0) req++;
    if(spl==0) req++;
    while(req+l<6) req++;
    return req;
}

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