#include<stdio.h>

int main()
{
	int money = 0;
	int total = 0;
	int empty = 0;
 
 
	scanf("%d", &money);
	
	//·½·¨2
	if(money <= 0)
	{
		total = 0;
	}
	else
	{
		total = money*2-1;
	}
	printf("total = %d\n", total);
 
 
	return 0;
}