Binary Addition

import java.util.*;

public class BinaryAddition {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        int x, y;
        System.out.println("ENTER THE TWO BINARY NUMBERS : ");
        x = sc.nextInt();
        y = sc.nextInt();
        StringBuffer s1 = new StringBuffer();
        StringBuffer s2 = new StringBuffer();
        StringBuffer s3 = new StringBuffer("");
        while (x != 0) {
            s1.append(x % 2);
            x /= 2;
        }
        while (y != 0) {
            s2.append(y % 2);
            y /= 2;
        }

        if (s1.length() > s2.length()) {
            for (int i = 0; i < s1.length() - s2.length(); i++)
                s2.append("0");
        } else {
            for (int i = 0; i < s2.length() - s1.length(); i++)
                s1.append("0");
        }

        int flag = 0;
        for (int i = 0; i < s1.length(); i++) {
            if (flag == 0) {
                if (s1.charAt(i) == '0' && s2.charAt(i) == '0')
                    s3.append("0");
                if (s1.charAt(i) == '1' && s2.charAt(i) == '0')
                    s3.append("1");
                if (s1.charAt(i) == '0' && s2.charAt(i) == '1')
                    s3.append("1");
                if (s1.charAt(i) == '1' && s2.charAt(i) == '1') {
                    flag = 1;
                    s3.append("0");
                }

            } else {
                if (s1.charAt(i) == '0' && s2.charAt(i) == '0') {
                    s3.append("1");
                    flag = 0;
                }
                if (s1.charAt(i) == '1' && s2.charAt(i) == '0') {
                    s3.append("0");
                    flag = 1;
                }
                if (s1.charAt(i) == '0' && s2.charAt(i) == '1') {
                    s3.append("0");
                    flag = 1;
                }
                if (s1.charAt(i) == '1' && s2.charAt(i) == '1') {
                    flag = 1;
                    s3.append("1");
                }
            }
        }

        if (flag == 1)
            s3.append("1");
        System.out.println("SUM IS " + s3.reverse());
    }
}