# -*- coding: utf-8 -*-

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

X.sort()
ans = 1000001
for i in range(N-1):
    a = X[i]
    b = X[i+1]
    dist = abs(a-b)
    if a!=b:
        ans = min(ans, dist)

print(0) if ans == 1000001 else print(ans)