#include <bits/stdc++.h>
#include <ctype.h>
using namespace std;

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
    string special_characters = "!@#$%^&*()-+";
    int flag[5]={0,0,0,0,0};
    int cntr=0;
    // flag small,big,digit,special,length respectively
    for(int i=0;i<n;i++)
    {
        if(islower(password[i]))
            flag[0]=1;
            
        if(isupper(password[i]))
            flag[1]=1;
                
        if(isdigit(password[i]))
            flag[2]=1;
           
        for(int j=0;j<special_characters.size();j++){
        if(password[i]==special_characters[j])
            flag[3]=1;
        }
                
                
        if(password.size()>=6)
            flag[4]=1;
                    
       
                    
              }
    
    for(int j=0;j<4;j++)
    {
        if (flag[j]==0)
            cntr++;
    }
    
    
    while(cntr+password.size()<6){
        if(password.size()>=6 &&cntr!=0)
        break;
        cntr++;
    }
        
        
    
    return cntr;
}

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