def interpolationSearch(arr, lo, hi, x):


	if (lo <= hi and x >= arr[lo] and x <= arr[hi]):


		pos = lo + ((hi - lo) // (arr[hi] - arr[lo]) *
					(x - arr[lo]))

		if arr[pos] == x:
			return pos

		if arr[pos] < x:
			return interpolationSearch(arr, pos + 1,
									hi, x)

		if arr[pos] > x:
			return interpolationSearch(arr, lo,
									pos - 1, x)
	return -1

arr = list(map(int,input("Enter the array elements: ").split()))
n = len(arr)

x = int(input("enter the number to search: "))
index = interpolationSearch(arr, 0, n - 1, x)

if index != -1:
	print("Element found at index", index)
else:
	print("Element not found")