N = int(input())
lsX = list(set(map(int,input().split())))
if len(lsX) == 1:
    print(0)
    exit()
lsX.sort()
ans = 10**10
for i in range(len(lsX)-1):
    ans = min(ans,lsX[i+1]-lsX[i])
print(ans)