#include <bits/stdc++.h>
#include<cctype>
using namespace std;

int minimumNumber(int n, string password) {
   int a=0,b=0,c=0,d=0,e=0,count=0;size_t special;int l[password.length()]={};int q[4]={};
   for(int i=0;i<password.length();i++)
   {
	if(password.length()>6)
	{
		e++;
	}
   	if(isdigit(password[i]))
   	{
   	a++;
		
	}
	if(islower(password[i]))
	{
	b++;	
	}
	if(isupper(password[i]))
	{
		c++;
	}
	
	if (password.find_first_not_of("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890_") != std::string::npos)
{
    d++;
}
	
	
	
   }
	q[0]=a;
	q[1]=b;
	q[2]=c;
	q[3]=d;
	q[4]=e;
	for(int i=0;i<5;i++)
	{
		if(q[i]==0)
		{
			count++;
		}
	}
	while(count+(password.length())<6)
   {
   		count++;}
   	return count;
}

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