n = int(input())
a = [int(i) for i in input().split()]
a.sort()
ans = []
for i in range(n-1):
    d = a[i+1] - a[i]
    if d != 0:
        ans.append(d)
ans.sort()
if len(ans) == 0:
    print(0)
else:
    print(ans[0])