import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int k = in.nextInt();
        String s = in.next();
        int n=s.length();
        int t1=0;
        int t2=0;
        int t3=0;
        int t4=0;
        String [] ar1={"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
          String [] ar2={"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
          String [] ar3={"0","1","2","3","4","5","6","7","8","9"};
          String [] ar4={"!","@","#","$","%","^","&","*","(",")","-","+"};
        
        for(int i=0;i<26;i++){
               for(int j=0;j<n;j++){
                if(ar1[i].equals(s.substring(j,j+1))){
                    t1=t1+1;
            }
            
        }
        }
           for(int i1=0;i1<26;i1++){
               for(int j1=0;j1<n;j1++){
                if(ar2[i1].equals(s.substring(j1,j1+1))){
                    t2=t2+1;
            }
            
        }}
                  for(int i2=0;i2<10;i2++){
               for(int j2=0;j2<n;j2++){
                if(ar3[i2].equals(s.substring(j2,j2+1))){
                    t3=t3+1;
            }
            
        }}
                         for(int i3=0;i3<12;i3++){
               for(int j3=0;j3<n;j3++){
                if(ar4[i3].equals(s.substring(j3,j3+1))){
                    t4=t4+1;
            }
            
        }}
                             if(t1>0)
                                 t1=1;
                              if(t2>0)
                                 t2=1;
                              if(t3>0)
                                 t3=1;
                              if(t4>0)
                                 t4=1;
                             int z11= n+4-t1-t2-t3-t4;
                                int b11=6-z11;
                             
 if(z11>=6){
     System.out.println(4-t1-t2-t3-t4);
 }
      if(z11<6){
           System.out.println(4+b11-t1-t2-t3-t4);
          
      }                       
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
    }
}