Problem:
Power

For given integers m and n, compute mn (mod 1,000,000,007). Here, A (mod M) is the remainder when A is divided by M.

Input

m n

Two integers m and n are given in a line.

Output

Print mn (mod 1,000,000,007) in a line.

Constraints

1 ≤ m ≤ 100

1 ≤ n ≤ 109

Sample Input 1

2 3

Sample Output 1

8

Sample Input 2

5 8

Sample Output 2

390625

Solution in Scala (judge verdict: Wrong Answer)

object Main {
  def main(args: Array[String]): Unit = {
    val Array(m, n) = io.StdIn.readLine().split(" ").map(_.toInt)
    println(power(m, n))
  }

  def power(m: Int, n: Int): BigInt = {
    def loop(m: BigInt, n: Int, acc: Int): Int = {
      n match {
        case 0 => acc
        case _ if n % 2 == 0 => loop(m * m, n / 2, acc)
        case _ => loop(m, n - 1, (m % 1000000007).toInt * acc)
      }
    }
    loop(m, n, 1)
  }
}