input()
xs = list(set(map(int,input().split())))
len_x = len(xs)
distances = set()
for i in range(len_x - 1):
    current = xs[i]
    for j in range(i + 1,len_x):
        distances.add(abs(current - xs[j]))
min_distance = 0
if distances:
    distances = sorted(list(distances))
    min_distance = distances[0]
print(min_distance)