#include <bits/stdc++.h>
using namespace std;
string to_string(const string& s) { return '"' + s + '"'; }
string to_string(const char* s) { return to_string((string)s); }
string to_string(bool b) { return (b ? "true" : "false"); }
string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (long long i = 0; i < static_cast<long long>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}
template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}
template <class A, class B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <class A, class B, class C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}
template <class A, class B, class C, class D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}
template <class A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto& x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
template <class Arg1>
void __f(const char* name, Arg1&& arg1) {
  cerr << name << " : " << to_string(arg1) << "\n";
}
template <class Arg1, class... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << " : " << to_string(arg1) << " | ";
  __f(comma + 1, args...);
}
const long long inf = (long long)4e18;
long long sum(long long x) {
  long long s = 0;
  for (; x; x /= 10) {
    s += (x % 10);
  }
  return s;
}
long long to_int(string s) {
  long long res = 0;
  for (long long i = 0; i < (long long)s.size(); i++) {
    res *= 10;
    res += s[i] - '0';
  }
  return res;
}
void solve() {
  long long n, k;
  cin >> n >> k;
  long long ans = inf;
  for (long long d = 0; d < 10; d++) {
    for (long long cnt = 0; cnt < 18; cnt++) {
      long long cur = cnt * 9 + d;
      if (cur > n) break;
      long long x = 0;
      for (long long i = 0; i < cnt; i++) {
        x += 9;
        x *= 10;
      }
      x += d;
      long long su = 0;
      for (long long i = 0; i <= k; i++) {
        su += sum(x + i);
      }
      69;
      su -= max(0LL, k + 1 - (10 - d));
      if (su > n) continue;
      for (long long d1 = 0; d1 < 9; d1++) {
        long long p = min(k + 1, 10 - d);
        long long new_su = su + d1 * p + (d1 + 1) * (k + 1 - p);
        if (new_su > n) continue;
        if (new_su == n) {
          if (d1 > 0) {
            string tmp = to_string(d1) + to_string(x);
            ans = min(ans, to_int(tmp));
          } else {
            ans = min(ans, x);
          }
          continue;
        }
        long long rem = n - new_su;
        if (rem % (k + 1) != 0) continue;
        rem /= (k + 1);
        long long f = rem % 9;
        rem -= f;
        for (long long it = 0; it < rem / 9; it++) {
          f *= 10;
          f += 9;
        }
        if (f > 0) {
          f *= 10;
          f += d1;
        }
        69;
        if (f == 0) {
          ans = min(ans, x);
        } else {
          string q = to_string(f) + to_string(x);
          ans = min(ans, to_int(q));
        }
      }
    }
  }
  if (ans == inf) {
    cout << "-1\n";
  } else {
    cout << ans << "\n";
  }
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  long long tt;
  cin >> tt;
  while (tt--) {
    solve();
  }
  return 0;
}
