#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    int count=0,f1=1,f2=1,f3=1,f4=1;
    for(int i=0;i<n;i++)
    {
        if(password[i]>='0' && password[i]<='9')
            f1=0;
        else if(password[i]>='a' && password[i]<='z')
            f2=0;
        else if(password[i]>='A' && password[i]<='Z')
            f3=0;
        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]=='&')
            f4=0;
    }
    //cout<<f1<<f2<<f3<<endl;
    count=f1+f2+f3+f4;
    if(n>6)
        return count;
    if(n<6 && count<6-n)
        return 6-n;
    return count;
}

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