#include "library.h"

void speak(int n)
{ if (n==0)
    print("zero");
  else if (n==1)
    print("one");
  else if (n==2)
    print("two");
  else if (n==3)
    print("three");
  else if (n==4)
    print("four");
  else if (n==5)
    print("five");
  else if (n==6)
    print("six");
  else if (n==7)
    print("seven");
  else if (n==8)
    print("eight");
  else if (n==9)
    print("nine");
  else if (n==10)
    print("ten");
  else if (n==11)
    print("eleven");
  else if (n==12)
    print("twelve");
  else if (n==13)
    print("thirteen");
  else if (n==14 || n==16 || n==17 || n==19)
  { speak(n-10);
    print("teen"); }
  else if (n==15)
    print("fifteen");
  else if (n==18)
    print("eighteen");
  else if (n==20)
    print("twenty");
  else if (n==30)
    print("thirty");
  else if (n==40)
    print("forty");
  else if (n==50)
    print("fifty");
  else if (n==80)
    print("eighty");
  else if (n==60 || n==70 || n==90)
  { speak(n/10);
    print("ty"); }
  else if (n>=21 && n<=99)
  { const int ty = n - n%10;
     // this just removes last digit, e.g. 37 -> 30
    speak(ty);
    print(" ");
    speak(n-ty); }
  else if (n>=100 && n<=999)
  { speak(n/100);
    const int lasttwo = n%100;
    if (lasttwo == 0)
      print(" hundred");
    else
    { print(" hundred and ");
      speak(lasttwo); } }
  else if (n>=1000 && n<=999999)
  { speak(n/1000);
    const int lastthree = n%1000;
    print(" thousand");
    if (lastthree != 0)
    { print(" ");
      speak(lastthree); } }
  else if (n>=1000000 && n<999999999)
  { speak(n/1000000);
    const int lastsix = n%1000000;
    print(" million");
    if (lastsix != 0)
    { print(" ");
      speak(lastsix); } }
  else if (n>=1000000000)
  { speak(n/1000000000);
    const int lastnine = n%1000000000;
    print(" billion");
    if (lastnine != 0)
    { print(" ");
      speak(lastnine); } }
  else // n must be negative then
  { print("minus ");
    speak(-n); } }