#include <bits/stdc++.h>
using namespace std;
template <typename T, size_t N>
int size(const T (&t)[N]) {
  return N;
}
template <typename T>
int size(const T &t) {
  return t.size();
}
string to_string(const string s, int x1 = 0, int x2 = 1e9) {
  return '"' + ((x1 < s.size()) ? s.substr(x1, x2 - x1 + 1) : "") + '"';
}
string to_string(const char *s) { return to_string((string)s); }
string to_string(const bool b) { return (b ? "true" : "false"); }
string to_string(const char c) { return string({c}); }
template <size_t N>
string to_string(const bitset<N> &b, int x1 = 0, int x2 = 1e9) {
  string t = "";
  for (int __iii__ = min(x1, size(b)), __jjj__ = min(x2, size(b) - 1);
       __iii__ <= __jjj__; ++__iii__) {
    t += b[__iii__] + '0';
  }
  return '"' + t + '"';
}
template <typename A, typename... C>
string to_string(const A(&v), int x1 = 0, int x2 = 1e9, C... coords);
int l_v_l_v_l = 0, t_a_b_s = 0;
template <typename A, typename B>
string to_string(const pair<A, B> &p) {
  l_v_l_v_l++;
  string res = "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
  l_v_l_v_l--;
  return res;
}
template <typename A, typename... C>
string to_string(const A(&v), int x1, int x2, C... coords) {
  int rnk = rank<A>::value;
  string tab(t_a_b_s, ' ');
  string res = "";
  bool first = true;
  if (l_v_l_v_l == 0) res += '\n';
  res += tab + "[";
  x1 = min(x1, size(v)), x2 = min(x2, size(v));
  auto l = begin(v);
  advance(l, x1);
  auto r = l;
  advance(r, (x2 - x1) + (x2 < size(v)));
  for (auto e = l; e != r; e = next(e)) {
    if (!first) {
      res += ", ";
    }
    first = false;
    l_v_l_v_l++;
    if (e != l) {
      if (rnk > 1) {
        res += '\n';
        t_a_b_s = l_v_l_v_l;
      };
    } else {
      t_a_b_s = 0;
    }
    res += to_string(*e, coords...);
    l_v_l_v_l--;
  }
  res += "]";
  if (l_v_l_v_l == 0) res += '\n';
  return res;
}
template <typename A, size_t N>
string to_string(const A (&v)[N], int x2) {
  return to_string(v, 0, x2);
}
void dbgm() { ; }
template <typename Heads, typename... Tails>
void dbgm(Heads H, Tails... T) {
  cout << to_string(H) << " | ";
  dbgm(T...);
}
const int MOD = 1e9 + 7;
const long long INF = 1e18;
const double EPS = 1e-9;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int t;
  cin >> t;
  for (int tt = 0; tt < t; tt++) {
    int n, k;
    cin >> n >> k;
    long long ans = INF;
    for (int d = 0; d < 10; d++) {
      for (int a = 0; a < 17; a++) {
        int cur = n - k * (k + 1) / 2;
        bool carry = k + 1 - (10 - d) > 0;
        if (carry) {
          if (a == 0) continue;
          cur += (k + 1 - (10 - d)) * (9 * a);
        } else {
          if (a > 0) continue;
        }
        if (cur % (k + 1)) continue;
        cur /= k + 1;
        int sum = d + 9 * max(a - 1, 0);
        if (sum > cur) continue;
        vector<int> num;
        num.push_back(d);
        for (int i = 0; i < a - 1; i++) {
          num.push_back(9);
        }
        while (sum < cur) {
          int add = min(9, cur - sum);
          if (carry && size(num) == a) {
            add = min(add, 8);
          }
          num.push_back(add);
          sum += add;
        }
        long long num2 = 0;
        for (int i = size(num) - 1; i > -1; i--) {
          num2 = num2 * 10 + num[i];
        }
        ans = min(ans, num2);
      }
    }
    if (ans == INF)
      cout << "-1\n";
    else
      cout << ans << '\n';
  }
  return 0;
}
