#include <iostream>
#include <string>
#include <stdio.h>
using namespace std;
int main()	{
	int n, i, count[]={0, 0, 0, 0}, r;
	string s;
	cin >> n >> s;
	int a[n];
	for (i=0; i<n; i++)	{
		a[i]=s[i];
		if (a[i]>=48 && a[i]<=57)	{
			count[0]=1;
		}
		else if (a[i]>=97 && a[i]<=122)	{
			count[1]=1;
		}
		else if (a[i]>=65 && a[i]<=90)	{
			count[2]=1;
		}
		else if ((35<=a[i] && a[i]<=38) ||  (40<=a[i] && a[i]<=43) || (a[i]==33) || (a[i]==45) || (a[i]==64) || (a[i]==94))	{
			count[3]=1;
		} 
	}
	r=4-count[0]-count[1]-count[2]-count[3];
	if (n+r>=6)	{
		printf("%d", r);
	}
	else	{
		printf("%d", 6-n);
	}
	return 0;
}