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

using ll = long long;
using i64 = long long;

void print(__int128_t x) {
    string res = "";
    while (x) {
        res += x % 10 + '0';
        x /= 10;
    }
    reverse(res.begin(), res.end());
    cout << res << "\n";
}

void solve() {
    i64 x, k;
    cin >> x >> k;

    vector<int> a(40);
    for (int i = 0; i < 20; ++i) {
        a[i] = x % 10;
        x /= 10;
    }
    if (k == 0) {
        __int128_t p = 1;
        for (int i = 0; i < 19; ++i, p *= 10) {
            if (a[i] != 9) {
                break;
            }
        }
        print(p);
        return;
    }
    __int128_t ans = (((__int128_t)1) << 127) - 1;
    for (int i = 0; i < 19; ++i) {
        auto b = a;
        int m = k;
        __int128_t y = 0, p = 1;
        for (int j = 0; j < 35; ++j, p *= 10) {
            if (j < i) continue;
            if (b[j] <= 9) {
                if (b[j] != 0 && m > 0) {
                    y += p * (10 - b[j]);
                    b[j + 1] += 1;
                    --m;
                }
            } else {
                --m;
                b[j + 1] += 1;
            }
        }
        if (m == 0) {
            ans = min(ans, y);
        }
    }

    print(ans);
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}