Right Gifts - Repovive Starter Round 7 | Repovive

21A. Right Gifts

500 pts1s256 MB

There are $n$ people and $n$ gifts, both numbered from $1$ to $n$ . Gift $i$ belongs to person $i$ .

You must distribute all the gifts so that each person receives exactly one gift and each gift is given to exactly one person.

Determine whether it is possible to distribute the gifts so that exactly $k$ people receive their own gifts.

Constraints

$1 \le k \le n \le 100$

Input

The input consists of two integers $n$ and $k$ :

n \quad k

Output

Print Yes if such a distribution is possible. Otherwise, print No.

The letter case does not matter. For example, YES, yes, and YeS are all accepted.

Samples

Input

5 2

Explanation

People $1$ and $2$ can receive gifts $1$ and $2$ . Then people $3$ , $4$ , and $5$ can receive gifts $4$ , $5$ , and $3$ , respectively. Exactly two people receive their own gifts.

Output

Yes

Input

4 3

Explanation

If three people receive their own gifts, the only remaining person must also receive their own gift because every other gift has already been used.

Output

No

There are $n$ people and $n$ gifts, both numbered from $1$ to $n$ . Gift $i$ belongs to person $i$ .

You must distribute all the gifts so that each person receives exactly one gift and each gift is given to exactly one person.

Determine whether it is possible to distribute the gifts so that exactly $k$ people receive their own gifts.

$1 \le k \le n \le 100$

The input consists of two integers $n$ and $k$ :

n \quad k

People $1$ and $2$ can receive gifts $1$ and $2$ . Then people $3$ , $4$ , and $5$ can receive gifts $4$ , $5$ , and $3$ , respectively. Exactly two people receive their own gifts.

My submissions

Announcements

My submissions

Announcements

My submissions

Announcements

My submissions

Announcements

21A. Right Gifts

Constraints

Input

Output

Samples

21A. Right Gifts

Constraints

Input

Output

Samples