1891: Remainders Game
Time Limit: 2 Sec Memory Limit: 256 MBSubmit: 0 Solved: 0
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Description
Today Pari and Arya are playing a game called Remainders.
Pari chooses two positive integer x and k, and tells Arya k but not x. Arya have to find the value 
. There are n ancient numbers c1,c2,...,cn and Pari has to tell Arya 
if Arya wants. Given k and the ancient values, tell us if Arya has a winning strategy independent of value of x or not. Formally, is it true that Arya can understand the value for any positive integer x?
Note, that 
means the remainder of x after dividing it by y.
The first line of the input contains two integers n and k (1≤n, k≤1000000)− the number of ancient integers and value k that is chosen by Pari.
The second line contains n integers c1,c2,...,cn (1≤ci≤1000000).
Print "Yes" (without quotes) if Arya has a winning strategy independent of value of x, or "No" (without quotes) otherwise.
4 5
2 3 5 12
Yes
2 7
2 3
No
In the first sample, Arya can understand 
because 5 is one of the ancient numbers.
In the second sample, Arya can't be sure what 
is. For example 1 and 7 have the same remainders after dividing by 2 and 3, but they differ in remainders after dividing by 7.