#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    int lo=0,d=0,u=0,l=0,s=0,req=0,other=0;
    string sp="!@#$%^&*()-+";
    if(n>=6)
     l=1;
    else
        req=6-n;
    for(int i=0;i<=n;i++)
    {  char c= password[i];
        if(isdigit(c))
            d=1;
       if(isupper(c))
            u=1;
        if(islower(c))
            lo=1;
     for(int j=0;j<12;j++)
     {
         if(password[i]==sp[j])
             s=1;
     }
     
        
    }
    if(req==3)       
    return req;
    else
    { if(d==0)
           other++;
     if(u==0)
         other++;
     if(lo==0)
         other++;
     if(s==0)
         other++;
    
    if(req<other)
        return other;
     else 
         return req;
    }
    
    // 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;
}