class Problem0135:
	def solve(this):
		n = int(input())
		x = set(map(int,input().split()))
		x = sorted(list(x))
		
		if len(x) == 1:
			print(0)
			return 
		
		res = []
		for i in range(len(x) - 1):
			d = abs(x[i+1] - x[i])
			res.append(d)
		print(min(res))
		
if __name__ == "__main__":
	problem = Problem0135()
	problem.solve()