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