import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class CupHolder {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int count = Integer.parseInt(br.readLine());
        String s = br.readLine();
        int answer = 1;
        for(int i = 0; i<count; i++) {
            if(s.charAt(i) == 'S') {
                answer++;
            } else {
                answer++;
                i++;
            }
        }
        if(answer > count) {
            answer = count;
        }
        System.out.println(answer);
    }
}