In the 2022 year, Mike found two binary integers a and b of length n (both of them are written only by digits 0 and 1) that can have leading zeroes. In order not to forget them, he wanted to construct integer d in the following way: 

  * he creates an integer c as a result of bitwise summing of a and b without transferring carry, so c may have one or more 2-s. For example, the result of bitwise summing of 0110 and 1101 is 1211 or the sum of 011000 and 011000 is 022000; 
  * after that Mike replaces equal consecutive digits in c by one digit, thus getting d. In the cases above after this operation, 1211 becomes 121 and 022000 becomes 020 (so, d won't have equal consecutive digits). 



Unfortunately, Mike lost integer a before he could calculate d himself. Now, to cheer him up, you want to find any binary integer a of length n such that d will be maximum possible as integer.

Maximum possible as integer means that 102 > 21, 012 < 101, 021 = 21 and so on.

Input

The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.

The first line of each test case contains the integer n (1 ≤ n ≤ 10^5) — the length of a and b.

The second line of each test case contains binary integer b of length n. The integer b consists only of digits 0 and 1.

It is guaranteed that the total sum of n over all t test cases doesn't exceed 10^5.

Output

For each test case output one binary integer a of length n. Note, that a or b may have leading zeroes but must have the same length n.

Example

Input


5
1
0
3
011
3
110
6
111000
6
001011


Output


1
110
100
101101
101110

Note

In the first test case, b = 0 and choosing a = 1 gives d = 1 as a result.

In the second test case, b = 011 so: 

  * if you choose a = 000, c will be equal to 011, so d = 01; 
  * if you choose a = 111, c will be equal to 122, so d = 12; 
  * if you choose a = 010, you'll get d = 021. 
  * If you select a = 110, you'll get d = 121. 

We can show that answer a = 110 is optimal and d = 121 is maximum possible.

In the third test case, b = 110. If you choose a = 100, you'll get d = 210 and it's the maximum possible d.

In the fourth test case, b = 111000. If you choose a = 101101, you'll get d = 212101 and it's maximum possible d.

In the fifth test case, b = 001011. If you choose a = 101110, you'll get d = 102121 and it's maximum possible d.
import java.io.*;
import java.util.*;

public class Main {

    public static void main(String[] args) throws IOException {
        int tc = sc.nextInt();
        while(tc-- > 0){
            int n = sc.nextInt();
            String b = sc.nextLine();
            int last = 7;
            StringBuilder ans = new StringBuilder();
            for(char c : b.toCharArray()){
                if(Integer.parseInt(c+"") + 1 != last) {
                    ans.append(1);
                    last = Integer.parseInt(c+"") + 1;
                }
                else if(Integer.parseInt(c+"") != last) {
                    ans.append(0);
                    last = Integer.parseInt(c+"");
                }
            }
            pw.println(ans);
        }

        pw.close();
    }

    public static void pairSort(Pair[] arr) {
        ArrayList<Pair> l = new ArrayList<>();
        for (Pair i : arr) l.add(i);
        Collections.sort(l);
        for (int i = 0; i < arr.length; i++) {
            arr[i] = l.get(i);
        }
    }
    public static void longSort(long[] arr) {
        ArrayList<Long> l = new ArrayList<>();
        for (long i : arr) l.add(i);
        Collections.sort(l);
        for (int i = 0; i < arr.length; i++) {
            arr[i] = l.get(i);
        }
    }
    public static void intSort(int[] arr) {
        ArrayList<Integer> l = new ArrayList<>();
        for (int i : arr) l.add(i);
        Collections.sort(l);
        for (int i = 0; i < arr.length; i++) {
            arr[i] = l.get(i);
        }
    }

    static class Scanner {
        StringTokenizer st;
        BufferedReader br;

        public Scanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

        public String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }

        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        public long nextLong() throws IOException {
            return Long.parseLong(next());
        }

        public String nextLine() throws IOException {
            return br.readLine();
        }

        public double nextDouble() throws IOException {
            String x = next();
            StringBuilder sb = new StringBuilder("0");
            double res = 0, f = 1;
            boolean dec = false, neg = false;
            int start = 0;
            if (x.charAt(0) == '-') {
                neg = true;
                start++;
            }
            for (int i = start; i < x.length(); i++)
                if (x.charAt(i) == '.') {
                    res = Long.parseLong(sb.toString());
                    sb = new StringBuilder("0");
                    dec = true;
                } else {
                    sb.append(x.charAt(i));
                    if (dec)
                        f *= 10;
                }
            res += Long.parseLong(sb.toString()) / f;
            return res * (neg ? -1 : 1);
        }

        public boolean ready() throws IOException {
            return br.ready();
        }

        public int[] nextIntArr(int n) throws IOException {
            int[] arr = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = Integer.parseInt(next());
            }
            return arr;
        }

        public long[] nextLongArr(int n) throws IOException {
            long[] arr = new long[n];
            for (int i = 0; i < n; i++) {
                arr[i] = Long.parseLong(next());
            }
            return arr;
        }

    }
    static class Pair implements Comparable<Pair>{
        int first, second;
        public Pair(int first, int second){
            this.first = first; this.second = second;
        }

        @Override
        public int compareTo(Pair p2) {
            return first - p2.first;
        }

        @Override
        public String toString() { return "("+ first + "," + second + ')'; }

    }

    static PrintWriter pw = new PrintWriter(System.out);
    static Scanner sc = new Scanner(System.in);
    static final int MOD = (int) 1e9 + 7;
    static Random random = new Random();
}