def first_player_wins(a, b):
    """
    If tie                    : Returns  0
    If first player wins      : Returns  1
    If second player wins     : Returns -1
    """
    if a == b:
        return 0
    elif [a, b] == ["R", "S"] or [a, b] == ["S", "P"] or [a, b] == ["P", "R"]:
        return 1
    return -1