#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
#include <queue>
#include <unordered_map>
#include <unordered_set>
#include <map>
#include <set>
#include <cmath>
#include <bitset>
#include <cassert>
#include <numeric>

using namespace std;
typedef long long ll;
typedef __int128 lll;

void print(lll x)
{
    if (!x) return;
    print(x / 10);
    cout << (ll)(x % 10);
}

lll pw[20];

void solve()
{
    lll f[20][20][2];
    memset(f, 0x3f, sizeof f);

    string s;
    cin >> s;
    reverse(s.begin(), s.end());
    int k;
    cin >> k;
    
    f[0][0][0] = 0;
    int n = s.size();
    s = " " + s;

    if (k == 0)
    {
        int cnt = 0;
        for (int i = 1; i <= n; i ++)
            if (s[i] == '9') cnt ++;
            else break;
        cout << 1;
        while (cnt --) cout << 0;
        cout << '\n';
        return;
    }

    for (int i = 1; i <= max(n, k); i ++)
        for (int j = 0; j <= k; j ++)
        {
            int u;
            if (i <= n) u = s[i] - '0';
            else u = 0;

            if (j)
            {
                f[i][j][1] = f[i - 1][j - 1][1] + (9 - u) * pw[i - 1];
                if (u) f[i][j][1] = min(f[i - 1][j - 1][0] + (10 - u) * pw[i - 1], f[i][j][1]);
            }

            f[i][j][0] = f[i - 1][j][0];
            if (u != 9) f[i][j][0] = min(f[i][j][0], f[i - 1][j][1]);
        }
    
    print(min(f[max(n, k)][k][0], f[max(n, k)][k][1]));
    cout << '\n';
}

int main()
{
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    pw[0] = 1;
    for (int i = 1; i < 20; i ++)
        pw[i] = pw[i - 1] * 10;
    
    int tt = 1;
    cin >> tt;
    while (tt --)
    {
        solve();
    }
    return 0;
}