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Contest: Task: Related: TaskB

Score : $300$ points

Problem Statement

You are given a string $S$ consisting of lowercase English letters. Another string $T$ is initially empty. Determine whether it is possible to obtain $S = T$ by performing the following operation an arbitrary number of times:

  • Append one of the following at the end of $T$: dream, dreamer, erase and eraser.

Constraints

  • $1≦|S|≦10^5$
  • $S$ consists of lowercase English letters.

Input

The input is given from Standard Input in the following format:

$S$

Output

If it is possible to obtain $S = T$, print YES. Otherwise, print NO.

Sample Input 1

erasedream

Sample Output 1

YES

Append erase and dream at the end of $T$ in this order, to obtain $S = T$.

Sample Input 2

dreameraser

Sample Output 2

YES

Append dream and eraser at the end of $T$ in this order, to obtain $S = T$.

Sample Input 3

dreamerer

Sample Output 3

NO