Java program to multiply two numbers upto 100000 places

Here's I'd created a Java program by which you can be able to multiply any two integer numbers upto 100000 places.
e.g., if you had to multiply
    99999999999999999999999999999999999999999999999
X  99999999999999999999999999999999999999999999999
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*******What will be the output of your program??????*******
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Here's my program:

import java.util.Scanner;

/**
 *
 * @author Mohammad Faisal
 * B.Tech.(IT)
 *
 */
public class MultiplyUptoAnyPlace {
    public static void main(String...args){
        /*try{
            int t[]=new int[126533629];
            System.out.println("Feel free to calculate upto "+t.length+" places.");
            System.out.println(Runtime.getRuntime().totalMemory());
        }catch(Exception e){}*/
        //System.exit(0);
        System.out.print("Enter first number: ");
        Scanner input=new Scanner(System.in);
        String str=input.next();
        int[] a=new int[str.length()];
        for(int i=0;i<str.length();i++){
            a[i]=Integer.parseInt(str.substring(i, i+1));
        }
        /*for(int i:a){
            System.out.print(i);
        }*/
        System.out.print("Enter second number: ");
        str=input.next();
        int[] b=new int[str.length()];
        for(int i=0;i<str.length();i++){
            b[i]=Integer.parseInt(str.substring(i, i+1));
        }
        /*for(int i:b){
            System.out.print(i);
        }*/
        MultiplyUptoAnyPlace m=new MultiplyUptoAnyPlace();
        m.multiply(a, b);
    }
    public String multiply(int[] a,int[] b){
        int i,j,k,l,carry,remainder,result[][],sum[];
        result=new int[b.length][a.length+b.length];
        sum=new int[a.length+b.length];
        String str="";
        i=0;j=0;k=0;carry=0;remainder=0;
        for(i=b.length-1;i>=0;i--){
            l=a.length+b.length-1-k;
            for(j=a.length-1;j>=0;j--){
                /*for(){
                  
                }*/
                str=((b[i]*a[j])+carry)+"";
                if(str.length()>1){
                    carry=Integer.parseInt(str.substring(0,1));
                    remainder=Integer.parseInt(str.substring(1));
                }else{
                    carry=0;
                    remainder=Integer.parseInt(str.substring(0));
                }
                result[k][l]=remainder;
                l--;
            }
            result[k][l]=carry;
            carry=0;
            /*for(int m=l-1;m>=0;m--){
                result[k][m]=0;
            }*/
            k++;
        }
        for(int c[]:result){
            for(int d:c){
                System.out.print(d);
            }
            System.out.println();
        }
        //carry=0;
        for(j=result[0].length-1;j>=0;j--){
            for(i=0;i<result.length;i++){
                sum[j]+=result[i][j];
            }
            str=sum[j]+carry+"";
            System.out.println("str contains: "+str);
            if(str.length()>1){
                sum[j]=Integer.parseInt(str.substring(str.length()-1));
                System.out.println("if>1 sum[j]: "+sum[j]);
                carry=Integer.parseInt(str.substring(0, str.length()-1));
                System.out.println("if>1 carry is: "+carry);
            }else{
                sum[j]=Integer.parseInt(str.substring(0));
                System.out.println("sum[j]: "+sum[j]);
                carry=0;
                System.out.println("carry is: "+carry);
            }
        }
        str="";
        for(int c:sum){
            System.out.print(c);
            str+=c;
        }
        System.out.println("\nOutput: \n"+str);
        return str;
    }
}