#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
    int i,l,u,c,in;
    l=u=in=i=c=0;
    for(i=0;i<n;i++)
    {
        if(password[i]>=65 && password[i]<=90)
            l++;
        else if(password[i]>=97 && password[i]<=122)
            u++;
        else if(password[i]>=48 && password[i]<=57)
            in++;
        else if(password[i]=='!' || password[i]=='@' || password[i]=='#' || password[i]=='$' || password[i]=='%' || password[i]=='^' || password[i]=='&' || password[i]=='*' || password[i]=='(' || password[i]==')' || password[i]== '-' || password[i]=='+')
            c++;
    }
    int ans=0;
    if(l==0)ans++;
    if(u==0)ans++;
    if(in==0)ans++;
    if(c==0)ans++;
    
    if((n+ans) >= 6 )
        return ans;
    
    ans+= (6-(n+ans));
    return ans;
    
}

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