package main

import . "fmt" 

func main() {
	var pa,pb int64
	Scan(&pa,&pb)
	var a,b,ans int64
	ans=1e18
	for a=0;a<=1e3;a++ {
		for b=0;b<=1e3;b++ {
			if a+b==0 {
				continue
			}
			ta:=(5+1e3*a/(a+b))/10
			tb:=(5+1e3*b/(a+b))/10
			if ta==pa&&tb==pb&&a+b<ans {
				ans=a+b
			}
		}
	}
	Println(ans)
	
}