'''
該問題類似於雞兔同籠問題，輸入腿和頭的個數，計算豬和雞的個數，採用窮舉法解決該問題。該問題來源於MIT計算機導論課程。
'''

def calculate(n_heads,n_legs):
    for n_chicks in range(0,n_heads+1):
        n_pigs=n_heads-n_chicks
        total_legs=4*n_pigs+2*n_chicks
        if total_legs==n_legs:
            return[n_pigs,n_chicks]
    return [None,None]
    
def solve():
    legs=int(input("輸入腿的個數："))
    heads=int(input("輸入頭的個數："))
    [pigs,chicks]=calculate(heads,legs)
    if pigs==None:
        print("輸入值無解")
    else:
        print("豬的個數為：",pigs)
        print("雞的個數為：",chicks)


solve()