#include <stdio.h>

float average(float a, float b);    /* Declaration */

main()
{
	float x, y, z;

	printf("Enter three numbers: ");
	scanf("%f%f%f", &x, &y, &z);
	printf("Average of %g and %g: %g\n", x, y, average(x, y));
	printf("Average of %g and %g: %g\n", y, z, average(y, z));
	printf("Average of %g and %g: %g\n", x, z, average(x, z));

	return 0;

}

float average(float a, float b)     /* Definition */
{
	return (a + b) / 2;
} 

