#include<stdio.h>
#include<string.h>

int main(void)
{
	int base=0,out=0,score=0,e,i,j;
	char str[10];
	for(;;){
		scanf("%d",&e);
		if(e==0)break;
		for(i=0;i<e;){
			scanf("%s",&str);
			if(!strcmp(str,"HIT"))base++;
			
			else if(!strcmp(str,"OUT")){
				out++;
			}
			
			else if(!strcmp(str,"HOMERUN")){
				score=score+base+1;
				base=0;
			}
			if(base>3){
				base--;
				score++;
			}
			if(out==3){
				out=0;
				printf("%d\n",score);
				i++;
				base=0;
				score=0;
			}
		}
	}
	return 0;
}