A9221 | Prime Number

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  on a piece of paper. After Simon led all fractions to a common denominator and summed them up, he got a fraction: , 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 $1000000007$ ( $10^{9}+7$ ).

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 $a_{1},a_{2},...,a_{n}$ ( $0<=a_{1}<=a_{2}<=...<=a_{n}<=10^{9}$ ).

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