First & Last X Digits

Java code:

import java.util.*;
public class Hello {

    public static void main(String[] args) {
        //Your Code Here
Scanner s=new Scanner(System.in);
String st;
int x,l,m=0,f=0;
st=s.next();
char ch[]=st.toCharArray();
x=s.nextInt();
l=ch.length-x;
for(int i=0;i<ch.length;i++)
{
    if(ch[i]!='0'||f==1)
    {
        if(m<x)
        {
            f=1;
            System.out.print(ch[i]);
            m++;
        }
    }
}
System.out.println();
for(int i=l;i<ch.length;i++)
System.out.print(ch[i]);
    }
}