atcoder#ABC240C. [ABC240C] Jumping Takahashi

[ABC240C] Jumping Takahashi

Score : 300300 points

Problem Statement

Takahashi is standing at the coordinate 00 on a number line.

He will now perform NN jumps. In the ii-th jump (1iN)(1 \leq i \leq N), he moves aia_i or bib_i in the positive direction.

Is it possible for him to be at the coordinate XX after NN jumps?

Constraints

  • 1N1001 \leq N \leq 100
  • 1ai<bi100(1iN)1 \leq a_i \lt b_i \leq 100 \, (1 \leq i \leq N)
  • 1X100001 \leq X \leq 10000
  • All values in input are integers.

Input

Input is given from Standard Input in the following format:

NN XX

a1a_1 b1b_1

\vdots

aNa_N bNb_N

Output

If it is possible for Takahashi to be at the coordinate XX after NN jumps, print Yes; otherwise, print No.

2 10
3 6
4 5
Yes

By moving b1(=6)b_1 (= 6) in the first jump and a2(=4)a_2 (= 4) in the second jump, he can be at the coordinate X(=10)X (= 10).

2 10
10 100
10 100
No

He can be at the coordinate X(=10)X (= 10) after the first jump, but not after all jumps.

4 12
1 8
5 7
3 4
2 6
Yes