program to change number system

#include<iostream.h>
#include<conio.h>
#include<iomanip.h>
void main()
{
    int a;
    clrscr();
    cout<<"enter the value of a";
    cin>>a;
    cout<<"\nhexadecimal number: "<<setiosflags(ios::hex)<<a;
    cout<<"\ndecimal number: "<<setiosflags(ios::dec)<<a;
    cout<<"\noctal number: "<<setiosflags(ios::oct)<<a;
    cout<<"\nthe value of a "<<a;
    getch();
}