source_code: import java.io.OutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.util.List;
  import java.util.StringTokenizer;
  import java.io.IOException;
  import java.io.BufferedReader;
  import java.util.Collections;
  import java.io.InputStreamReader;
  import java.util.ArrayList;
  import java.io.InputStream;
  
  public class C909 {
      public static void main(String[] args) {
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          InputReader in = new InputReader(inputStream);
          PrintWriter out = new PrintWriter(outputStream);
          TaskA solver = new TaskA();
          solver.solve(1, in, out);
          out.close();
      }
  
      static class TaskA {
          public void solve(int testNumber, InputReader in, PrintWriter out) {
              int n = in.nextInt();
              int ar[] = new int[n+1];
              int count = 1;
              ar[0] = 1;
              for(int i=0;i<n;i++){
                  char c = in.next().charAt(0);
                  if(c == 'f')
                      count++;
                  else{
                      for(int j=1;j<count;j++){
                          ar[j] = (ar[j] + ar[j-1])% (int)(1e9+7);
                      }
                  }    
              }
              out.println(ar[count-1]);
          }
      }
  
      static class InputReader {
          public BufferedReader reader;
          public StringTokenizer tokenizer;
  
          public InputReader(InputStream stream) {
              reader = new BufferedReader(new InputStreamReader(stream), 32768);
              tokenizer = null;
          }
  
          public String next() {
              while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                  try {
                      tokenizer = new StringTokenizer(reader.readLine());
                  } catch (IOException e) {
                      throw new RuntimeException(e);
                  }
              }
              return tokenizer.nextToken();
          }
  
          public int nextInt() {
              return Integer.parseInt(next());
          }
  
          public long nextLong() {
              return Long.parseLong(next());
          }
  
          public double nextDouble() {
              return Double.parseDouble(next());
          }
  
          public String nextLine() {
              String str = "";
              try
              {
                  str = reader.readLine();
              }
              catch (IOException e)
              {
                  e.printStackTrace();
              }
              return str;
          }
      }
  }