#include <iostream>
#include <string>
using namespace std;

int main(void){
  string res;
  int n,cnt=0,cntH=0,point=0;

    cin >> n;
  for( int i = 0 ; i < n ;){
    cin >> res;
    
    if( res == "OUT" ){
      cnt++;
      if( cnt == 3 ){
	i++;
	cnt = 0;
	cout << point << endl;
	point = 0;
	cntH = 0;
      }
    }
    else if( res == "HIT" ){
      cntH++;
      if( cntH == 4 ){
	point++; cntH--;
      }
    }
    else{
      point += cntH+1;
      cntH = 0;
    }
      
      
      }
  return 0;
}