#Python program-4 linear search using recursive function
def linear_search(arr, key, size):
    if size == 0:
        return -1
    elif arr[size - 1] == key:
        return size - 1
    else:
        return linear_search(arr, key, size - 1)

arr = [10, 20, 30, 40, 50]
key = 20
size = len(arr)
ans = linear_search(arr, key, size)

if ans != -1:
    print('The element', key, 'is found at', ans, 'index of the given array')
else:
    print('The element', key, 'is not found')