source_code: import java.io.*;
  import java.util.*;
  
  public class A{
  	InputStream is;
  	PrintWriter out;
  	String INPUT = "";
  	
  	public void solve(){
  		int n=ni();
  		char[] arr=new char[n];
  		for(int i=0;i<n;i++){
  			arr[i]=ns().charAt(0);
  		}
  
  		long mod=1000000007;
  		long[][] memo=new long[n][n];
  		memo[0][0]=1L;
  		int k=0;
  		for(int i=1; i<n; i++){
  			if( (arr[i]=='f' && arr[i-1]=='s') || (arr[i]=='s' && arr[i-1]=='s') ){
  				long sum=0;
  				for(int j=k; j>=0; j--){
  					sum=(sum+(memo[i-1][j]%mod))%mod;
  					memo[i][j]=sum;
  				}
  			}
  			else{
  				k+=1;
  				for(int j=1; j<=k; j++){
  					memo[i][j] = memo[i-1][j-1] % mod;
  				}
  			}
  		}
  		//print(n, memo);
  		long sum=0;
  		for(int i=0;i<=k;i++){
  			sum=(sum+(memo[n-1][i])%mod)%mod;
  		}
  		out.println(sum);
  	}
  	void print(int n, long[][] memo){
  		for(int i=0;i<n;i++){
  			for(int j=0;j<n;j++){
  				out.print(memo[i][j]+" ");
  			}
  			out.println();
  		}
  	}
  
  	void run(){
  		is = new DataInputStream(System.in);
  		out = new PrintWriter(System.out);
  		int t=1;while(t-->0)solve();
  		out.flush();
  	}
  	public static void main(String[] args)throws Exception{new A().run();}
  	//Fast I/O code is copied from uwi code.
  	private byte[] inbuf = new byte[1024];
  	public int lenbuf = 0, ptrbuf = 0;
  	private int readByte(){
  		if(lenbuf == -1)throw new InputMismatchException();
  		if(ptrbuf >= lenbuf){
  			ptrbuf = 0;
  			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
  			if(lenbuf <= 0)return -1;
  		}
  		return inbuf[ptrbuf++];
  	}
  	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
  	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
  	private double nd() { return Double.parseDouble(ns()); }
  	private char nc() { return (char)skip(); }
  	private String ns(){
  		int b = skip();
  		StringBuilder sb = new StringBuilder();
  		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
  			sb.appendCodePoint(b);
  			b = readByte();
  		}
  		return sb.toString();
  	}
  	private char[] ns(int n){
  		char[] buf = new char[n];
  		int b = skip(), p = 0;
  		while(p < n && !(isSpaceChar(b))){
  			buf[p++] = (char)b;
  			b = readByte();
  		}
  		return n == p ? buf : Arrays.copyOf(buf, p);
  	}
  	private char[][] nm(int n, int m){
  		char[][] map = new char[n][];
  		for(int i = 0;i < n;i++)map[i] = ns(m);
  		return map;
  	}
  	private int[] na(int n){
  		int[] a = new int[n];
  		for(int i = 0;i < n;i++)a[i] = ni();
  		return a;
  	}
  	private int ni(){
  		int num = 0, b;
  		boolean minus = false;
  		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
  		if(b == '-'){
  			minus = true;
  			b = readByte();
  		}
  		
  		while(true){
  			if(b >= '0' && b <= '9'){
  				num = num * 10 + (b - '0');
  			}else{
  				return minus ? -num : num;
  			}
  			b = readByte();
  		}
  	}
  	private long nl(){
  		long num = 0;
  		int b;
  		boolean minus = false;
  		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
  		if(b == '-'){
  			minus = true;
  			b = readByte();
  		}
  		
  		while(true){
  			if(b >= '0' && b <= '9'){
  				num = num * 10 + (b - '0');
  			}else{
  				return minus ? -num : num;
  			}
  			b = readByte();
  		}
  	}
  	static  int i(long x){return (int)Math.round(x);}
  	static class Pair implements Comparable<Pair>{
  		long fs,sc;
  		Pair(long a,long b){
  			fs=a;sc=b;
  		}
  		public int compareTo(Pair p){
  			if(this.fs>p.fs)return 1;
  			else if(this.fs<p.fs)return -1;
  			else{
  				return i(this.sc-p.sc);
  			}
  			//return i(this.sc-p.sc);
  		}
  		public String toString(){
  			return "("+fs+","+sc+")";
  		}	
  	}
  	
  }