// URL--> 

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

#define OPTIMIZE ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define WHITE 1111
#define GREY 2222
#define BLACK 3333
#define ll long long int
const ll maxn = 1e6+6 ;
const ll MOD = 1e9 + 7;
//----------------------------------------functions------
bool comparator(int i , int j)
{
    return (i < j);
}

ll gcd(ll x, ll y)
{
	ll t;
	while(y != 0)
	{
		t = x%y;
		x = y;
		y = t;
	}
	return x;
}
//----------------------------------------main------
int main()
{
	OPTIMIZE
	
	int n,ctr=0;
	string s;
	string special = "!@#$%^&*()-+";


	cin>>n;
	cin>>s;

	int flagup=0,flaglow=0,flagdig=0,flagspec=0;

	for (int i = 0; i < n; ++i)
	{
		if(s[i]>='A'&&s[i]<='Z')
			flagup=1;
		else if(s[i]>='a'&&s[i]<='z')
			flaglow=1;
		else if(s[i]>='0'&&s[i]<='9')
			flagdig=1;
		else
		{
				for (int j = 0; j < special.length(); ++j)
				{
					if(s[i]==special[j])
					{
						flagspec=1;
						break;
					}
				}
		}

	}

	ctr=abs(flagspec-1)+abs(flagdig-1)+abs(flaglow-1)+abs(flagup-1);
	if (n+ctr<6)
	{
		ctr=ctr+ (6-(n+ctr));
	}

	cout<<ctr;

	return 0;
}