#include <bits/stdc++.h>

using namespace std;


int main() {
    int n;
    cin >> n;
    string password;
    cin >> password;
    
    int d=1,l=1,u=1,s=1;
    int temp=0;
    
    if(password.length()<6)
        temp = 6-password.length();
   
    for(int i=0 ; i<password.length() ; i++)
    {
        if((int)(password[i])>=48 and (int)(password[i])<=57)
            d=0;
        else if((int)(password[i])>=65 and (int)(password[i])<=90)
            u=0;
        else if((int)(password[i])>=97 and (int)(password[i])<=122)
            l=0;
        else if(password[i]=='!' or password[i]=='@' or password[i]=='#' or password[i]=='$' or password[i]=='%' or password[i]=='^' or password[i]=='&' or password[i]=='*' or password[i]=='(' or password[i]==')' or password[i]==')' or password[i]=='-' or password[i]=='+' )
            s=0;
    }

    cout << max(temp,d+u+l+s) << endl;

    return 0;
}