A,B=map(int,input().split())
ans=10**10
for a in range(1000):
	for b in range(1000):
		if a==b==0:
			continue
		if ((1000*a)//(a+b)+5)//10==A and ((1000*b)//(a+b)+5)//10==B:
			ans=min(ans,a+b)
print(ans)