Program without a function

*Example of a program without functions*/
/*temperature conversion program*/
#include <stdio.h>
#include <math.h>
#define TRUE 1
#define FALSE 0

int main()
{
   int answer_1;
    double celsius;
    double fahr;
 

   answer_1=TRUE;
  
   while(answer_1==TRUE) {
      printf("\nInput degrees Fahrenheit for conversion to Celsius (^z to exit):  \n");
      scanf("%lf",&fahr);
      celsius=((fahr-32.0)*5.)/9.;
      printf("\n%lf Celcius\n\n", celsius);
      printf("\nAnother F to C conversion?  (0 to exit conversion):  \n");
      scanf("%d", &answer_1);
   }
   printf("\nDo you want to input degrees in Celsius for conversion? (yes=1)\n");
   scanf("%d", &answer_1);
   
    while(answer_1==TRUE) {
      printf("\n\nInput degrees Celsius for conversion to Fahrenheit (^z to exit):  \n");
      scanf("%lf",&celsius);
      fahr=(9.0/5.0)*celsius+32.0;
      printf("\n\n%lf Fahrenheit. \n\n",fahr);
      printf("\nAnother C to F conversion?  (0 to exit conversion):  \n");
      scanf("%d", &answer_1);
     }
  
   printf("\n\nEnd of program \n");
   return (0);
  
}