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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n,i,up=0,lo=0,dig=0,special=0,count=0;
    string s;
    cin>>n;
    cin>>s;
    
    for(i=0;i<n;i++){
        if(isupper(s[i]))
            up++;
        else if(islower(s[i]))
            lo++;
        else if(isdigit(s[i]))
            dig++;
        else if(s[i]=='!' || s[i]=='@' || s[i]=='#' || s[i]=='$' || s[i]=='%' || s[i]=='^' || s[i]=='&' || s[i]=='*' ||s[i]=='(' ||             s[i]==')' ||s[i]=='-' || s[i]=='+')
             special++;
                
    }
    
    if(up==0)
        count++;
    if(lo==0)
        count++;
    if(dig==0)
        count++;
    if(special==0)
        count++;
    
    if((n+count)>=6)
         cout<<count;
    
    else{
       int temp=6-n;
       if(count>temp)
           cout<<count;
       else 
           cout<<temp;
        
    } 
        
        
    return 0;
}