#include<bits/stdc++.h>
using namespace std;
#define ll long long 
#define fr first
#define sc second
#define MAX ((ll)(1e18+100))
#define MOD ((ll)(1e9+7))
#define HS1 ((ll)(137))
#define HS2 ((ll)(1e9+9))
#define ARRS ((ll)(1e6+900))
#define pb push_back
#define mid ((l+r)>>1)
#define PI 3.14159265358979323846


int main(){
	ll n;
	string s;
	cin>>n;
	cin>>s;
	ll d=1,l=1,u=1,sp=1;
	for(int i=0; i<n; i++){
		if('0'<=s[i]&&s[i]<='9')
			d=0;
		else if('a'<=s[i]&&s[i]<='z')
			l=0;
		else if('A'<=s[i]&&s[i]<='Z')
			u=0;
		else 
			sp=0;
	}
	cout<<max({0ll,d+l+u+sp,6-n});
	return 0;
}