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

distance=[]

if N!=1:
    for i in range(N-1):
        distance.append(abs(X[i]-X[i+1]))
else:
    pass

distance=[i for i in distance if i!=0]

if len(X)!=0:
    print(min(distance))
else:
    print(0)