N = int(input())
X = list(map(int,input().split(" ")))

a = sorted([abs(X[i] - X[i + 1]) for i in range(N) if i + 1 < N])

if a[0] == 0:
    print(a[1])
elif sum(a) == 0:
    print(0)
else:
    print(a[0])