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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n;
    cin>>n;
    string s;
    cin>>s;
  string  numbers = "0123456789";
  string lower = "abcdefghijklmnopqrstuvwxyz";
   string upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
   string special = "!@#$%^&*()-+";
    bool num=false,sp=false,up=false,low=false;
    int cnt=0;
    for(int i=0;i<n;i++){
        if(num==false){
            for(int j=0;j<numbers.length();j++){
                if(s[i]==numbers[j]){
                    num=true;
                    cnt++;
                    break;
                }
            }
        }
        if(low==false){
            for(int j=0;j<lower.length();j++){
                if(s[i]==lower[j]){
                    low=true;
                    cnt++;
                    break;
                }
            }
        }
        if(up==false){
            for(int j=0;j<upper.length();j++){
                if(s[i]==upper[j]){
                    up=true;
                    cnt++;
                    break;
                }
            }
        }
        if(sp==false){
            for(int j=0;j<special.length();j++){
                if(s[i]==special[j]){
                    sp=true;
                    cnt++;
                    break;
                }
            }
        }
    }
    cnt=4-cnt;
    int x=n+cnt;
    if(x<6){
        x=6;
    }
    cout<<x-n;
    return 0;
}