Problems

# Circle of choirs

# Circle of choirs

A section of choral singing operates in school. The start of the section always happens in the same way: by the signal of the header of the section all **n** participants stand in a circle and each **m**-th person sings a gamut for singing.

The leader of the section noticed that all the members are not always able to stretch their vocal cords. Given **n** and **m**, help him to determine whether or not all the choir participants will take part in the warm-up again.

#### Input

Consists of 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**", otherwise "**NO**".

Input example #1

4 1 6 3

Output example #1

YES NO