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: Wrong Answer)

using System;

public class hello
{
    public static void Main()
    {
        string[] line = Console.ReadLine().Trim().Split(' ');
        var m = ulong.Parse(line[0]);
        var n = ulong.Parse(line[1]);
        var a = 1000000007UL;
        var ans = Power(m, n ,a);
        Console.WriteLine(ans);
    }
    public static ulong Power(ulong m, ulong n, ulong a)
    {
        if (n == 0) return 1;
        var res = (ulong)Math.Pow((m * m) % a, n / 2);
        if (n % 2 == 1) res = (res * m) % a;
        return res;
    }
}