#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include<string>
using namespace std;


int main() {
   int n;
   cin >> n;
   string numbers = "0123456789";
 string lower_case = "abcdefghijklmnopqrstuvwxyz";
string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string special_characters = "!@#$%^&*()-+" ;
    bool c1=0,c2=0,c3=0,c4=0;
       

        string s ;
        cin>>s;
        for(int i = 0;i<n;i++){
            if(numbers.find(s[i])!=string::npos){
                c1=1;
            }else if(lower_case.find(s[i])!=string::npos){
                c2=1;
            }else if(upper_case.find(s[i])!=string::npos){
                c3=1;
            }else if(special_characters.find(s[i])!=string::npos){
                c4=1;
            }
            
        }
    int count = 0;
    if(c1==0)
        count++;
    if(c2==0)
                count++;
    if(c3==0)
        count++;
    if(c4==0)
          count++;
    
    if(n+count<6){
        count+= 6-n-count; 
    }
    cout<<count;
    return 0;
}