#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin>>n;
	string s;
	cin>>s;
	int x=6,tag=0,tag1=0,tag2=0,tag3=0;
	for(int i=0;i<n;i++)
	{
		if(s[i]-'0'>=0 && s[i]-'0'<=9)
		{
			tag=1;
		}
		else if(s[i]-'a'>=0 && s[i]-'a'<=25)
		{
			tag1=1;
		}
		else if(s[i]-'A'>=0 && s[i]-'A'<=25)
		{
			tag2=1;
		}
		else if(s[i]=='!' || s[i]=='%' || s[i]=='^' || s[i]=='&' || s[i]=='*' ||s[i]=='(' ||s[i]==')' ||s[i]=='$' || s[i]=='-' || s[i]=='+' || s[i]=='#' || s[i]=='@' )
		{
			tag3=1;
		}
	}
	int t=4-(tag+tag1+tag2+tag3);
	if(n>=6 || n+t>=6)
	{
		cout<<t<<endl;
	}
	else 
	{
		cout<<t+(6-(n+t))<<endl;
	}
	
}