source_code: import java.util.*;
  
  public class GFG {
      static int count=0;
      
  	public static void main (String[] args) {
  		Scanner ob=new Scanner(System.in);
  		int n;
  		long MOD=(long)(1e9+7);
  		int f=0,s=0;
  		n=ob.nextInt();
  		long dp[][]=new long[n+2][n+2];
  		dp[0][1]=1;
  		char ch='s';
  		char p;
  		for(int i=1;i<=n;i++)
  		{
  		    p=ch;
  		    ch=ob.next().charAt(0);
  		    if(p=='f')
  		    {
  		        for(int j=1;j<=n;j++)
  		        dp[i][j+1]=dp[i-1][j];
  		    }
  		    else
  		    {
  		        for(int j=n;j>0;j--)
  		        {
  		            dp[i][j]=(dp[i][j+1]+dp[i-1][j])%MOD;
  		        }
  		    }
  		}
  		
  		long ans=0;
  		
  		for(int i=1;i<=n;i++)
  		{
  		    ans=(ans+dp[n][i])%MOD;
  		}
  		System.out.println(ans);
  	}
  }