#include<stdio.h>
#include<stdbool.h>
#include<string.h>
int main()
{	
	int n;
	scanf("%d",&n);
	char str[n];
	bool pass[4];
	memset(pass,false,sizeof(pass));
	scanf("%s",str);int i;
	for(i=0;i<strlen(str);i++)
	{
		if(str[i]>='a'&&str[i]<='z')
			pass[0]=true;
		else	if(str[i]>='A'&&str[i]<='Z')
					pass[1]=true;
				else	if(str[i]>=48&&str[i]<=57)
							pass[2]=true;
						else	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]=='+')
									pass[3]=true;
	}
	int count=0;
	for(i=0;i<4;i++)
		if(!pass[i])
			count++;
	if(count+strlen(str)<6)
		printf("%d",6-(count+strlen(str))+count);
	else
		printf("%d",count);	
	printf("\n");
	return 0;
}