#include<stdio.h>
#include<string.h>
int main()
{
	int n,m,i,a=0;
	scanf("%d",&n);
	char str[n];
	scanf("%s",&str[0]);
	int s=0,u=0,l=0,d=0;
	for(i=0;i<n;i++)
	{
	
		if(str[i]=='!' ||str[i]=='@' ||str[i]=='#' ||str[i]=='$' ||str[i]=='%' ||str[i]=='^' ||str[i]=='&' ||str[i]=='*' ||str[i]=='(' ||str[i]==')' ||str[i]=='-' ||str[i]=='+')
		s++;
		if(str[i]=='A' || str[i]=='B' || str[i]=='C' || str[i]=='D' || str[i]=='E' || str[i]=='F' || str[i]=='G' || str[i]=='H' || str[i]=='I' || str[i]=='J' || str[i]=='K' || str[i]=='L' || str[i]=='M' || str[i]=='N' || str[i]=='O' || str[i]=='P' || str[i]=='Q' || str[i]=='R' || str[i]=='S' || str[i]=='T' || str[i]=='U' || str[i]=='V' || str[i]=='W' || str[i]=='X' || str[i]=='Y' || str[i]=='Z' )
		u++;
		if(str[i]=='a' || str[i]=='b' || str[i]=='c' || str[i]=='d' || str[i]=='e' || str[i]=='f' || str[i]=='g' || str[i]=='h' || str[i]=='i' || str[i]=='j' || str[i]=='k' || str[i]=='l' || str[i]=='m' || str[i]=='n' || str[i]=='o' || str[i]=='p' || str[i]=='q' || str[i]=='r' || str[i]=='s' || str[i]=='t' || str[i]=='u' || str[i]=='v' || str[i]=='w' || str[i]=='x' || str[i]=='y' || str[i]=='z')
		l++;
		if(str[i]=='0' || str[i]=='1' || str[i]=='2' || str[i]=='3' || str[i]=='4' || str[i]=='5' || str[i]=='6' || str[i]=='7' || str[i]=='8' || str[i]=='9' )
		d++;
	}
	if(n>=6)
	{
		if(s==0)
		a++;
		if(u==0)
		a++;
		if(l==0)
		a++;
		if(d==0)
		a++;
		printf("%d",a);
	}
	else
	{
		if(s==0)
		a++;
		if(u==0)
		a++;
		if(l==0)
		a++;
		if(d==0)
		a++;
		if(a+n<6)
		a=6-n;
		printf("%d",a);
	}
}