/* Demonstrates variables and constants */
#include <stdio.h>

/* Define a constant to convert from pounds to grams */
#define GRAMS_PER_POUND 454

/* Define a constant for the start of the next century */
const int NEXT_CENTURY = 2000;

/* Declare the needed variables */
long weight_in_grams, weight_in_pounds;
int year_of_birth, age_in_2000;

main()
{
      /* Input data from user */

      printf("Enter your weight in pounds: ");
      scanf("%d", &weight_in_pounds);
      printf("Enter your year of birth: ");
      scanf("%d", &year_of_birth);

      /* Perform conversions */

      weight_in_grams = weight_in_pounds * GRAMS_PER_POUND;
      age_in_2000 = NEXT_CENTURY - year_of_birth;

      /* Display results on the screen */

      printf("\nYour weight in grams = %ld.", weight_in_grams);
      printf("\nIn 2000 you will be %d years old.\n", age_in_2000);
      
      return 0;
}