N = int(input())
X = sorted([int(i) for i in input().split()])

inf = 10**9
ans = inf

for i in range(N - 1):
    if X[i] != X[i + 1]:
        ans = min(ans, X[i + 1] - X[i])

if ans < inf:
    print(ans)
else:
    print(0)