#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    
    int special=0, lCase=0, uCase=0, num=0;
    int count=0, r, i;
    for(i=0;i<n;i++)
    {
        r = password[i]-'0';
        if(r>=0 && r<=9)num++;
        else if(r>=17 && r<=42)uCase++;
        else if(r>=49 && r<=74)lCase++;
        else special++;
    }
    if(!num)count++;
    if(!uCase)count++;
    if(!lCase)count++;
    if(!special)count++;
    if(count+n <6)count=6-n;
    return count;
}

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