n = int(input())
x = [int(i) for i in input().split()]

x.sort()

dist = []
for i in range(n-1):
    dist.append(x[i+1]-x[i])
notZero = [i for i in dist if i!=0]
if len(notZero)!= 0:
    print(min(notZero))
else:
    print(0)