백준 1703번: 생장점 #Python

import sys

input = sys.stdin.readline

while 1:
    line = list(map(int, input().split()))

    if line[0] == 0:
        break
    
    leaf = 1
    
    for i in range(1, len(line), 2):
        leaf *= line[i]
        leaf -= line[i + 1]
    
    print(leaf)