#include <bits/stdc++.h>
#include<ctype.h>
using namespace std;
int minimumNumber(int n, string password) {int count=0;
    int c1=0,c2=0,c3=0,c4=0;
    for(int i=0;i<n;i++)
    {if(isdigit(password[i]))
        c1++;
     else if(isupper(password[i]))
        c2++;
     else if(islower(password[i]))
         c3++;
    else if(ispunct(password[i]))
        c4++;}
     if(!(c1>=1))
     {count++;
     c1++;}
       if(!(c2>=1))
     {count++;
     c2++;
     }
      if(!(c3>=1))
     {count++;
     c3++;}
      if(!(c4>=1))
     {count++;
     c4++;}
     int m=c1+c2+c3+c4;
     if(!((m)>=6))
         count=count+6-m;
     return count;
         
    // Return the minimum number of characters to make the password strong
}

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