n = int(input())

numList = list(map(int, input().split()))
numList = sorted(numList)

ret = null
for i in range(n):
    if (i == n - 1):
        break
    elif (numList[i] - numList[i + 1]):
        continue
    val = abs(numList[i] - numList[i + 1])
    print("min =")
    print(ret)
    if i == 0:
        # 初回の場合　無条件で最小値を代入
        ret = val
        continue;
    elif ret > abs(val):
        ret = val

if ret == null:
    ret = 0

print(ret)