Problems

# Circle of choirs

# Circle of choirs

In a school operates a circle of choral singing. Start mug always happen consistently: the signal head mug all **N** participants are in a circle and every **M**-th for raspevki singing styles.

Head of the circle noticed that stretch the vocal chords is not always possible to all participants of the circle. For given **N** and **M** help him to define, or once again in the warm-up will be attended by all members of the choir.

**Input**

The input file consists several cases. Each case contains two positive integers **N** and **M**. (**1** ≤ **N**, **M** ≤ **10 ^{3}**).

**Output**

If everyone has a chance to sing, print "**YES**", else "**NO**".

Input example

4 1 6 3

Output example

YES NO