INF = 10 ** 20
import sys
sys.setrecursionlimit(100000000)
dy = (-1,0,1,0)
dx = (0,1,0,-1)
from  heapq import heappop,heapify,heappush
from bisect import bisect_left

def main():
    a,b = map(int,input().split())
    if a > b:
        print(0)
    elif a == b:
        print(4)
    elif b < 2 * a:
        print(8)
    elif b == 2 * a:
        print(4)
    elif b > 2 * a:
        print(0)
if __name__ == '__main__':
    main()