source_code: import java.io.BufferedReader;
  import java.io.FileNotFoundException;
  import java.io.FileReader;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.StringTokenizer;
  
  public class C {
  
  
  	static ArrayList<Integer> statements;
  	static final int MOD = (int) 1e9 + 7;
  
  	static int[][] memo;
  
  	static int solve(int i, int c) {
  		if(i == statements.size())
  			return 1;
  		if(memo[i][c] != -1)
  			return memo[i][c];
  
  		long ans = solve(i + 1, c + statements.get(i));
  		if(c > 0)
  			ans += solve(i, c - 1);
  		return memo[i][c] = (int) (ans % MOD);
  
  	}
  
  	public static void main(String[] args) throws IOException {
  		Scanner sc = new Scanner(System.in);
  		PrintWriter out = new PrintWriter(System.out);
  
  		int n = sc.nextInt();
  		statements = new ArrayList<>();
  
  		char[] c = new char[n];
  		for (int i = 0; i < n; i++) {
  			c[i] = sc.next().charAt(0);
  		}
  
  		if(c[0] == 's')
  			statements.add(0);
  		else
  			statements.add(1);
  
  		for (int i = 1; i < n; i++) {
  			if(c[i - 1] == 'f') {
  				if(c[i] == 'f')
  					statements.set(statements.size() - 1, statements.get(statements.size() - 1) + 1);
  			}else {
  
  				if(c[i] == 's')
  					statements.add(0);
  				else
  					statements.add(1);
  			}
  		}
  
  
  		memo = new int[statements.size()][n + 1];
  
  		for(int[] a : memo)
  			Arrays.fill(a, -1);
  		out.println(solve(0, 0));
  		out.flush();
  		out.close();
  	}
  
  	static class Scanner {
  		StringTokenizer st;
  		BufferedReader br;
  
  		public Scanner(InputStream s) {
  			br = new BufferedReader(new InputStreamReader(s));
  		}
  
  		public Scanner(String file) throws FileNotFoundException {
  			br = new BufferedReader(new FileReader(file));
  		}
  
  		public String next() throws IOException {
  			while (st == null || !st.hasMoreTokens())
  				st = new StringTokenizer(br.readLine());
  			return st.nextToken();
  		}
  
  		public int nextInt() throws IOException {
  			return Integer.parseInt(next());
  		}
  
  		public long nextLong() throws IOException {
  			return Long.parseLong(next());
  		}
  
  		public String nextLine() throws IOException {
  			return br.readLine();
  		}
  
  		public double nextDouble() throws IOException {
  			String x = next();
  			StringBuilder sb = new StringBuilder("0");
  			double res = 0, f = 1;
  			boolean dec = false, neg = false;
  			int start = 0;
  			if (x.charAt(0) == '-') {
  				neg = true;
  				start++;
  			}
  			for (int i = start; i < x.length(); i++)
  				if (x.charAt(i) == '.') {
  					res = Long.parseLong(sb.toString());
  					sb = new StringBuilder("0");
  					dec = true;
  				} else {
  					sb.append(x.charAt(i));
  					if (dec)
  						f *= 10;
  				}
  			res += Long.parseLong(sb.toString()) / f;
  			return res * (neg ? -1 : 1);
  		}
  
  		public boolean ready() throws IOException {
  			return br.ready();
  		}
  
  	}
  }