RT

#include<bits/stdc++.h>
using namespace std;

unsigned long long ans;
void g114514(unsigned long long x,unsigned long long y)
{
	unsigned long long ma=min(x,y);
	if(x>y) x-=ma;
	else if(x<y) y-=ma;
	else x=0;
	ans+=ma*4;
	if(x==0) return;
	g114514(x,y);
	return;
}
int main()
{
	unsigned long long x,y;
	scanf("%llu %llu",&x,&y);
	g114514(x,y);
	printf("%llu",ans);
    return 0;
}