from typing import List
import random


def play_rng(player1: int, player2: int, skill_levels: List[int]) -> int:
    """
    player1 and player2 play RNG against each other
    the skill level of a player determines the number of marbles in the urn
    return the winner
    """
    skill_level1 = skill_levels[player1]
    skill_level2 = skill_levels[player2]
    # determine a random marble
    random_marble = random.randint(1, skill_level1 + skill_level2)
    # the owner of the drawn marble wins
    if random_marble <= skill_level1:
        return player1
    else:
        return player2