Finding Given Digit First Number in Fibonacci Series - Java

package com.nano.FiboDigit;
import java.io.*;
public class FiboDigit
 {
/**
*
* Author : Karthik
* Date  : 16-07-2012
*
*/
public static void main(String[] args) {
try
{
long f,f1,f2,digit,usrdigit,fdup;
f1=1;
f2=1;
f=f1+f2;
digit=1;
DataInputStream g=new DataInputStream(System.in);
do // ll reapeat the Process
{
System.out.println("Enter Digit : ");
usrdigit = Integer.parseInt(g.readLine());
System.out.println("Fibonacci Series :");
//System.out.println(f1);
//System.out.println(f2);
for(long i=1;i<=100;i++)
{
digit=1;
f1=f2;
f2=f;
f=f1+f2;
fdup=f;
//System.out.println("The First "+usrdigit+" digit number is: "+ f);
while((fdup/10)>0) // for finding first given digit number
{
digit = digit+1;
fdup=fdup/10;
}
if(digit==usrdigit)
{
System.out.println("The First "+usrdigit+" digit number is: "+ f);
//System.exit(0);
break;
}
//System.out.println("The First "+usrdigit+" digit number is: "+ f)
} //for loop ends here
}
while(true);  // do...while end's here
}   // try block ends here
catch(Exception e)
{
}
} //main method ends here
} //class ends here