#include<iostream>
#include<algorithm>
#include<vector>
#include<cstring>
#include<string>

using namespace std;

#define sz(x) (int)(x.size())
#define fi(a,b) for(int i=a;i<b;++i)
#define fj(a,b) for(int j=a;j<b;++j)
#define fo(a,b) for(int o=a;o<b;++o)
#define fdi(a,b) for(int i=a-1;i>=b;--i)
#define fdj(a,b) for(int j=a-1;j>=b;--j)
#define fdo(a,b) for(int o=a-1;o>=b;--o)
#define pb push_back
#define mp make_pair
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll, ll> pll;
//////////////////


void solve(){
	string numbers = "0123456789";
	string lower_case = "abcdefghijklmnopqrstuvwxyz";
	string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	string special_characters = "!@#$%^&*()-+";
	string s;
	int n;
	cin >> n;
	cin >> s;
	bool a = true, b = true, c = true, d = true;
	fi(0, n){
		if(numbers.find(s[i]) != string::npos) a = 0;
		if(lower_case.find(s[i]) != string::npos) b = 0;
		if(upper_case.find(s[i]) != string::npos) c = 0;
		if(special_characters.find(s[i]) != string::npos) d = 0;
	}
	int ans = 0;
	ans += a;
	ans += b;
	ans += c;
	ans += d;
	ans = max(ans, 6 - n);
	cout << ans << endl;
}

int main(){
#ifdef _DEBUG
	freopen("input.txt","r",stdin);
	freopen("output.txt","w",stdout);
#endif

	solve();


	return 0;
}