Solve in Python:
Simon has a prime number x and an array of non-negative integers a_1, a_2, ..., a_{n}.

Simon loves fractions very much. Today he wrote out number $\frac{1}{x^{a} 1} + \frac{1}{x^{a_{2}}} + \ldots + \frac{1}{x^{a_{n}}}$ on a piece of paper. After Simon led all fractions to a common denominator and summed them up, he got a fraction: $\frac{s}{t}$, where number t equals x^{a}_1 + a_2 + ... + a_{n}. Now Simon wants to reduce the resulting fraction. 

Help him, find the greatest common divisor of numbers s and t. As GCD can be rather large, print it as a remainder after dividing it by number 1000000007 (10^9 + 7).


-----Input-----

The first line contains two positive integers n and x (1 ≤ n ≤ 10^5, 2 ≤ x ≤ 10^9) — the size of the array and the prime number.

The second line contains n space-separated integers a_1, a_2, ..., a_{n} (0 ≤ a_1 ≤ a_2 ≤ ... ≤ a_{n} ≤ 10^9). 


-----Output-----

Print a single number — the answer to the problem modulo 1000000007 (10^9 + 7).


-----Examples-----
Input
2 2
2 2

Output
8

Input
3 3
1 2 3

Output
27

Input
2 2
29 29

Output
73741817

Input
4 5
0 0 0 0

Output
1



-----Note-----

In the first sample $\frac{1}{4} + \frac{1}{4} = \frac{4 + 4}{16} = \frac{8}{16}$. Thus, the answer to the problem is 8.

In the second sample, $\frac{1}{3} + \frac{1}{9} + \frac{1}{27} = \frac{243 + 81 + 27}{729} = \frac{351}{729}$. The answer to the problem is 27, as 351 = 13·27, 729 = 27·27.

In the third sample the answer to the problem is 1073741824 mod 1000000007 = 73741817.

In the fourth sample $\frac{1}{1} + \frac{1}{1} + \frac{1}{1} + \frac{1}{1} = \frac{4}{1}$. Thus, the answer to the problem is 1.
n, x = map(int, input().split())
t = list(map(int, input().split()))
b = max(t)
k = t.count(b)
r = sum(t)
s = r - b
while k % x == 0:
    b -= 1
    s += 1
    k = k // x + t.count(b)
print(pow(x, min(r, s), 1000000007))