//Author : Ayush Jain

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

#define ull unsigned long long
#define ll long long
#define mod 1000000007
#define fi first
#define se second
const int N=1e5 + 5;
const int M=1e5 + 5;

ull pw[67];
void pre()
{
	pw[0]=1;
	for(int i=1;i<64;i++) pw[i]=2*pw[i-1];
}

int main()
{
	ios_base::sync_with_stdio(false);
	pre();
	char s[105];
	char b1[]="0123456789";
	char b2[]="abcdefghijklmnopqrstuvwxyz";
	char b3[]="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	char b4[]="!@#$%^&*()-+";
	int n,i,j;
	cin>>n;
	cin>>s;
	bool a1=false,a2=false,a3=false,a4=false;	
	int ans=0;
	for(i=0;i<n;i++){
		for(j=0;j<strlen(b1);j++){
			if(s[i]==b1[j]) a1=true;
		}
		for(j=0;j<strlen(b2);j++){
			if(s[i]==b2[j]) a2=true;
		}
		for(j=0;j<strlen(b3);j++){
			if(s[i]==b3[j]) a3=true;
		}
		for(j=0;j<strlen(b4);j++){
			if(s[i]==b4[j]) a4=true;
		}
	}
	if(!a1) ans++;
	if(!a2) ans++;
	if(!a3) ans++;
	if(!a4) ans++;
	if(ans+n>=6) cout<<ans<<endl;
	else cout<<ans+(6-(ans+n))<<endl;
		
	return 0;
}