1085

# include <stdio.h>
# include <math.h>
main()
{
	float x,y;
	scanf("%f",&x);
	if(x<0)
	{
		y=fabs(x);
	}
	else if(x>=0&&x<2)
	{
		y=pow(x+1,1.0/2.0);
	}
	else if(x>=2&&x<4)
	{
		y=pow(x+2,5);
	}
	else if(x>=4)
	{
		y=2*x+5;
	}
	printf("%.2f",y);
}