No output-only black console window

The output of the following C program is three integers-let us assume x,y,z.Find (x+y+z).

Please, you are informed that this C program can be compiled by turbo C compiler.

#include<stdio.h>
#include<conio.h>
   main()
   {
     int a=1;
     printf("%d\n%d\n%d\n",a,++a,a++);
     getch();
    }