#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
   string nos = "0123456789";
string lc = "abcdefghijklmnopqrstuvwxyz";
string uc = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string sc = "!@#$%^&*()-+";
    int x=4;
    int i;
    for(i=0;i<n;i++)
    {
        if(password[i]>=65&&password[i]<=90)
        {x--;
         break;
        }
    }
     for(i=0;i<n;i++)
    {
        if(password[i]>=97&&password[i]<=122)
        {x--;
         break;
        }
    }
     for(i=0;i<n;i++)
    {
        if(password[i]>=48&&password[i]<=57)
        {x--;
         break;
        }
    }
     for(i=0;i<n;i++)
    {
        if(password[i]=='!'||password[i]=='@'||password[i]=='#'||password[i]=='$'||password[i]=='^'||password[i]=='&'||password[i]=='*'||password[i]=='('||password[i]==')'||password[i]=='-'||password[i]=='+')
        {x--;
         break;
        }
    }
    if(n>=6)
        return x;
    else
        return
        max(6-n,x);
    
}

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