M = int(input())
N = list(map(int, input().split(" ")))
N.sort()
#print(N)
array = []
for i in range(M - 1):
    target = N[i + 1] - N[i]
    if target != 0:
        array.append(target)
array.sort()
if array != []:
    print(array[0])
else:
    print("0")