Biggest Out of 3

#include<iostream.h>
#include<conio.h>
 void main()
 {
 clrscr();
 int a,b,c;
 cout<<"enter 1st no\n";
 cin>>a;
 cout<<"enter 2nd no\n";
 cin>>b;
 cout<<"enter 3rd no\n";
 cin>>c;
 if(a>b)
 if(a>c)
 cout<<"a is bigger\n";
 else
 cout<<"c is bigger\n";
 else if(b>c)
 cout<<"b is bigger\n";
 else
 cout<<"c is bigger";
 getch();
 }