/*
 *  globalvar.c
 */
#include <stdio.h>

float int_average(void);

int xx, yy; // declare global variables before main

int main(void)
{
  float avrg;
  puts("This program calculates the average of two numbers.");
  printf("Enter two integers separated by a space: ");
  scanf("%d%d", &xx, &yy);
  avrg = int_average();

  printf("The average is %.2f.\n",avrg );

  return 0;
}

float int_average(void)
{
  return (xx+yy)/2.0;
}