#include <iostream>
using namespace std;
int main()
{
	int n,m;
	cin >> n >> m;
	int posX = 0,posY = 0;
	int velocityX = 1, velocityY = 1;
	int times = 1;
	while(true)
	{
		if(posX + velocityX > m - 1 || posX + velocityX < 0)
		{
			times ++;
			
			if(velocityX > 0)
			{
				velocityX = -1;
			}
			else
			{
				velocityX = 1;			
			}
		}
		if(posY + velocityY > n - 1 || posY + velocityY < 0)
		{
			times ++;
			
			if(velocityY > 0)
			{
				velocityY = -1;
			}
			else
			{
				velocityY = 1;			
			}
		}
		posX += velocityX;
		posY += velocityY;
		if(((posX == 0 && posY == 0) || (posX == 0 && posY == n - 1) || (posX == m - 1 && posY == n - 1) || (posX == m - 1 && posY == 0)) && times > 0)
		{
			break;
		}
	}
	
	cout << times << endl;
	return 0;
}
