题目描述
100 years have passed since the last victory of the man versus computer in Go. Technologies made a huge step forward and robots conquered the Earth! It's time for the final fight between human and robot that will decide the faith of the planet.
The following game was chosen for the fights: initially there is a polynomial
P(x) = anxn + an - 1xn - 1 + ... + a1x + a0,
Polynomial P(x) is said to be divisible by polynomial Q(x) if there exists a representation P(x) = B(x)Q(x), where B(x) is also some polynomial.
Some moves have been made already and now you wonder, is it true that human can guarantee the victory if he plays optimally?
Input
The first line of the input contains two integers n and k (1 ≤ n ≤ 100 000, |k| ≤ 10 000) — the size of the polynomial and the integer k.
The i-th of the following n + 1 lines contain character '?' if the coefficient near xi - 1 is yet undefined or the integer value ai, if the coefficient is already known ( - 10 000 ≤ ai ≤ 10 000). Each of integers ai (and even an) may be equal to 0.
Please note, that it's not guaranteed that you are given the position of the game where it's computer's turn to move.
Output
Print "Yes" (without quotes) if the human has winning strategy, or "No" (without quotes) otherwise.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
样例输出
提示
In the first sample, computer set a0 to - 1 on the first move, so if human can set coefficient a1 to 0.5 and win.
In the second sample, all coefficients are already set and the resulting polynomial is divisible by x - 100, so the human has won.