代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可

@param numbers int整型一维数组

@return int整型

class Solution:

def duplicate(self , numbers: List[int]) -> int:
    re = dict()
    for idx,val in enumerate(numbers):
        if  val not in re:
            re[val] = id
        else:
            return val
    print(re)
    if re == {}:
        return -1
        
    # write code here