PivotOJ

Pillow Stacking

시간 제한: 3000ms메모리 제한: 1024MB출처: ICPC Rocky Mountain Regional 2024-2025BOJ 32676

문제

Eleanor has recently lost her favorite pillow. Being very particular about her pillows, she categorizes pillows by their softness. The pillow she lost had softness CC, and she will be unable to sleep without this exact softness. While she has access to some other types of pillows, there may not be any of her desired softness. As a work-around, she is willing to sleep with multiple pillows in a stack. When pillows with softness C1,C2,,CkC_1, C_2, \ldots, C_k are stacked together in that order, the resulting softness is equal to \[ C_1 + \left\lceil \frac{C_2}{2} \right\rceil + \left\lceil \frac{C_3}{4} \right\rceil + \ldots + \left\lceil \frac{C_k}{2^{k-1}} \right\rceil. \] In other words, the iith pillow in the stack contributes 2(i1)2^{-(i-1)} of its softness, rounded up. Note that f\lceil f \rceil is defined as the smallest integer xx with xfx \geq f.

Eleanor has a lot of money and is willing to use an unlimited amount of each pillow type she has access to. Can you help her determine if there is a way to stack pillows to reach her desired softness?

입력

The first line of input contains two integers NN and CC (1N1031 \leq N \leq 10^3 and 1C1041 \leq C \leq 10^4). NN indicates the number of types of pillows Eleanor has access to, and CC indicates the desired softness level. The next line contains NN integers a1,a2,,aNa_1, a_2, \ldots, a_N (1ai10181 \leq a_i \leq 10^{18}), indicating the softness of pillows that Eleanor has access to.

출력

If it is possible for Eleanor to stack pillows to reach softness CC, output YES. Otherwise, output NO.

예제

예제 1

입력
1 1000
1
출력
YES

예제 2

입력
1 5
4
출력
NO

예제 3

입력
2 100
51 98
출력
YES
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