#include <bits/stdc++.h>
using namespace std;
using namespace chrono;

using ll = long long;
using ull = unsigned long long;

string to_string(const string &s) {
  return '"' + s + '"';
}

string to_string(bool b) {
  return b ? "true" : "false";
}

template <typename A, typename B>
string to_string(const pair<A, B> &p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename T>
string to_string(const T &v) {
  string s = "{";
  bool first = true;
  for (const auto &it : v) {
    if (!first)
      s += ", ";
    else
      first = false;
    s += to_string(it);
  }
  return s += "}";
}

void debug_out() {
  cerr << endl;
}

template <typename T, typename... Args>
void debug_out(const T &first, const Args&... rest) {
  cerr << to_string(first) << " ";
  debug_out(rest...);
}

#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

auto startTime = high_resolution_clock::now();
int get_time() {
  auto stopTime = chrono::high_resolution_clock::now();
  auto duration = duration_cast<milliseconds>(stopTime - startTime);
  return duration.count(); // in ms
}

void solve() {
  string s;
  cin >> s;
  
  ull r = 1;
  for (int i = s.size() - 1; i >= 0; --i) {
    s[i] += r;
    if (s[i] > '9') {
      s[i] = '0';
      r = 1;
    } else {
      r = 0;
    }
  }

  if (r == 1)
    s = '1' + s;

  ull m;
  cin >> m;

  r = 0;
  for (auto it : s) {
    r = (r * 10 + it - '0') % m;
  }

  ull ans = (r == 0) ? (0) : (m - r);

  string ms = to_string(m);

  ull add = 1; // cat mai am nevoie sa fac un ovf cu 1
  ull p = 1, k = 0, pf = 1;
  while (k + 1 < ms.size()) {
    ++k;
    p = p * 10;
  }

  for (int i = s.size() - ms.size(); i >= 0; --i) {
    string n = s.substr(i, ms.size());

    bool found = false;
    for (ull i = 0, p2 = p; i < ms.size(); ++i, p2 /= 10) {
      if (n[i] != ms[i]) {
        found = true;

        if (n[i] < ms[i]) {
          ull x = 0, y = 0;
          for (int j = i; j < ms.size(); ++j) {
            x = x * 10 + n[j] - '0';
            y = y * 10 + ms[j] - '0';
          }

          auto dif = y - x - 1;
          auto cost = dif * p + add;
          ans = min(ans, cost);
        } else {
          ull x = 0;
          for (int j = 0; j < ms.size(); ++j) {
            x = x * 10 + n[j] - '0';
          }

          auto cost = pf * ((p - x) + m - 1) + add;
          ans = min(ans, cost);
        }

        break;
      }
    }

    if (!found) {
      ans = 0; 
      break;
    }

    add = add + ('9' - s[i]) * pf;
    add = min(add, m);

    pf = pf * 10;
    pf = min(pf, m);
  }

  r = ans;
  for (int i = s.size() - 1; i >= 0; --i) {
    r = r + s[i] - '0';
    s[i] = '0' + r % 10;
    r = r / 10;
  }

  while (r > 0) {
    s.insert(0, 1, (char)(r % 10 + '0'));
    r /= 10;
  }

  cout << s << "\n";
}

int main() {
  cin.tie(NULL);
  ios_base::sync_with_stdio(false);

  int t = 1;
  cin >> t;
  while (t--)
    solve();

  return 0;
}