#include <stdio.h>
#include <conio.h>
main()
{
	float x,y,z;
	printf("Input x :");
	scanf("%f",&x);
	printf("\nInput y :");
	scanf("%f",&y);
	z=0.5*(x*y);
	printf("\nResult : %.2f",z);
	printf("\n By Suthasinee Thongman NO.26");
}