n=int(input())
list=[int(i) for i in input().split()]
c=10000000
d=0
for i in range(n-1):
    if list[i]-list[i+1]<0:
        d=(-1)*(list[i]-list[i+1])
    elif list[i]-list[i+1]>0:
        d=list[i]-list[i+1]
    if c>d:
        c=d
    i=i+1
print(c)