input()
xs = list(set(map(int,input().split())))
len_x = len(xs)
xs.sort(reverse=True)
min_distance = float("inf")
for i in range(len_x - 1):
    min_distance = min([min_distance,xs[i] - xs[i + 1]])
if min_distance == float("inf"):
    min_distance = 0
print(min_distance)