#include <bits/stdc++.h>
using namespace std;
void IMPLEMENT_CODE() {
  char s[200005];
  cin >> s;
  long long int l = strlen(s);
  long long int x;
  cin >> x;
  char ans[l + 1];
  char o = '1';
  char z = '0';
  for (long long int i = 0; i < l; ++i) {
    ans[i] = z;
  }
  ans[l] = '\0';
  for (long long int i = 0; i < l; i++) {
    if (s[i] == '1') {
      if (i + x < l) {
        if (i + 2 * x < l && s[i + 2 * x] == '1')
          ans[i + x] = o;
        else if (i + 2 * x >= l)
          ans[i + x] = o;
      }
      if (i - x >= 0) {
        if (i - 2 * x >= 0 && s[i - 2 * x] == '1')
          ans[i - x] = o;
        else if (i - 2 * x < 0)
          ans[i - x] = o;
      }
    }
  }
  char p[l + 1];
  p[l] = '\0';
  for (long long int i = 0; i < l; ++i) {
    p[i] = z;
  }
  for (long long int i = 0; i < l; i++) {
    if (i + x < l && ans[i + x] == '1') p[i] = o;
    if (i - x >= 0 && ans[i - x] == '1') p[i] = o;
  }
  if (strcmp(p, s) == 0)
    cout << ans << endl;
  else {
    int q = 1;
    for (long long int i = 0; i < l; i++) {
      if (s[i] == o && p[i] != o) {
        q = 0;
        break;
      }
    }
    if (q == 1)
      cout << ans << endl;
    else
      cout << -1 << endl;
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(0);
  ;
  long long int testCases;
  cin >> testCases;
  while (testCases--) {
    IMPLEMENT_CODE();
  }
  return 0;
}
