# https://leetcode.com/problems/find-champion-ii/
from typing import List


class Solution:
    def findChampion(self, n: int, edges: List[List[int]]) -> int:
        lose_team = [False] * n
        for [_, b] in edges:
            lose_team[b] = True
        champ = -1
        for i in range(len(lose_team)):
            if lose_team[i] == False:
                if champ != -1:
                    champ = -1
                    break
                else:
                    champ = i
        return champ