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 C# (judge verdict: Accepted)

using System;

public class Hello
{
    public const long E7 = 1000000007;
    public static void Main()
    {
        string[] line = Console.ReadLine().Trim().Split(' ');
        var m = long.Parse(line[0]);
        var n = long.Parse(line[1]);
        var ret = power(m, n) % E7;
        Console.WriteLine(ret);
    }
    public static long power(long x, long n)
    {
        if (n == 0) return 1L;
        if (n % 2 == 0)
        {
            var ww = (x * x) % E7;
            var t = power(ww, n / 2L) % E7;
            return t;
        }
        else
        {
            var t2 = power(x, n - 1) % E7;
            return x * t2;
        }
    }
}