#include<iostream>
using namespace std;
int main()
{
	char a[100];
	int n,d=0,u=0,l=0,s=0,c=0,c1=0,i;
	cin>>n;
	cin>>a;
	if(n<6)
	{
		c1=6-n;
	}
	for(i=0;i<n;i++)
	{
		if(a[i]>='A'&&a[i]<='Z')
			u++;
		else if(a[i]>='a'&&a[i]<='z')
			l++;
		else if(a[i]>='0'&&a[i]<='9')		
			d++;
		else if(a[i]=='!'||a[i]=='@'||a[i]=='#'||a[i]=='$'||a[i]=='%'||a[i]=='^'||a[i]=='&'||a[i]=='*'||a[i]=='('||a[i]==')'||a[i]=='-'||a[i]=='+')
			s++;
	}
	if(s==0)
		c++;
	if(u==0)
		c++;
	if(l==0)
		c++;
	if(d==0)
		c++;
	if(c1<=c)
		cout<<c;
	else
		cout<<c1;
	return 0;
	
}