# Write a function to find a pair with the highest product from a given array of integers.
def max_product(arr):
    arr_len = len(arr)
    if arr_len < 2:
        return None
    x = arr[0]
    y = arr[1]
    for i in range(0, arr_len):
        for j in range(i + 1, arr_len):
            if arr[i] * arr[j] > x * y:
                x = arr[i]
                y = arr[j]
    return x, y
