#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin>>n;
	char ar[n];
	cin>>ar;
	char ar2[12]={'!','@','#','$','%','^','&','*','(',')','-','+'};
	
	 int ucase=0,scase=0,dig=0,schar=0,count=0,res=0;
	for(int i=0;i<n;i++)
	{
		if(ar[i]>='a'&&ar[i]<='z')
			scase++;
		else if(ar[i]>='A'&&ar[i]<='Z')
			ucase++;
		else if(ar[i]>='0'&&ar[i]<='9')
			dig++;
		else
		{
			for(int j=0;j<12;j++)
			{
				if(ar[i]==ar2[j])
					schar++;
			}
				
		}
		
	}
	res=6-n;
		if(scase==0)
			count++;
		if(ucase==0)
			count++;
		if(dig==0)
			count++;
		if(schar==0)
			count++;
	if(n<6)
	{
		
		if(scase>0&&ucase>0&&dig>0&&schar>0)
			{
				
				cout<<res;
			}
		else 
		{
			
			if(res<count)
			{
				cout<<count;
			}
			else
				cout<<res;
			
		}
	}
	else
	{
		if(count==4)
			cout<<"0";
		else
		{
			cout<<count;
		}
	}
	 return 0;
	
}