N=int(input())
X=list(map(int,input().split()))
if sum(X)==0:
    print(0)
else:
    min=max(X)
    for i in range(1,N):
        if (abs(X[i]-X[i-1]))<min and abs(X[i]-X[i-1])!=0:
            min=abs(X[i]-X[i-1])
print(min)