text: // Fig. 2.5: fig02_05.c
  // Addition program.
  #include <stdio.h>
  
  // function main begins program execution
  int main(void)
  {
      int integer1 = 0; // first number to be entered by the user
      int integer2 = 0; // second number to be entered by the user
  
      // GPP 2.6
      // There is a convention associated later on with
      // variables that start with a capital letter.
      int Sum;
      int SUM;
  
      // GPP 2.7
      int sum_of_two_integers = 0;
      int sumOfTwoIntegers = 0;
  
      printf("Enter first integer\n"); // prompt
      scanf("%d", &integer1); // read an integer
  
      printf("Enter second integer\n"); // prompt
      scanf("%d", &integer2); // read an integer
  
      int sum = integer1 + integer2;
  
      printf("Sum is %d\n", sum);
  
      printf("%d + %d = %d\n", integer1, integer2, integer1 + integer2);
  }