# You are given an array of integers representing coordinates of obstacles situated on a straight line.

# Assume that you are jumping from the point with coordinate 0 to the right. 
# You are allowed only to make jumps of the same length represented by some integer.

# Find the minimal length of the jump enough to avoid all the obstacles.

# Example

# For inputArray = [5, 3, 6, 7, 9], the output should be
# avoidObstacles(inputArray) = 4.

# Check out the image below for better understanding:

def avoidObstacles(inputArray):

	step = 2

	while True:
		long = range(0,max(inputArray)+step,step)
		if len( [True for elem in long if elem not in inputArray ] ) == len(long):
			return step
		else:
			step = step + 1
