#include <bits/stdc++.h>
using namespace std;
#define int long long
int x, k;
int num[20], p[20];
int dp[20][20][2];
int c[110]; //
int f[110];
void work()
{
    cin >> x >> k;
    for (int i = 0; i < 18; i++)
    {
        num[i] = x % 10;
        x /= 10;
    }
    memset(dp, 0x3f, sizeof dp);
    dp[0][0][0] = 0;
    dp[0][1][1] = f[1] - num[0];
    for (int i = 1; i < 18; i++)
    {
        for (int l = 0; l <= 1; l++)
        {
            for (int j = 0; j <= i; j++)
            {
                int v = dp[i - 1][j][l];
                if (l == 1)
                {
                    int nd = 10 - num[i] - 1;
                    int cd = f[i] * nd;
                    dp[i][j + 1][1] = min(dp[i][j + 1][1], dp[i - 1][j][1] + cd);
                    if (nd != 0)
                    {
                        dp[i][j][0] = min(dp[i][j][0], dp[i - 1][j][1]);
                    }
                }
                else
                {
                    int nd = 10 - num[i];
                    int cd = f[i] * nd;
                    dp[i][j + 1][1] = min(dp[i][j + 1][1], dp[i - 1][j][0] + cd);
                    if (nd != 0)
                    {
                        dp[i][j][0] = min(dp[i][j][0], dp[i - 1][j][0]);
                    }
                }
            }
        }
    }
    // cout<<dp[1][1][1]<<endl;
    int v = dp[19][19][0];
    int ans = min(dp[17][k][0], dp[17][k][1]);
    if(ans==0)
    {
        for(int i=0;i<=18;i++)
        {
            if(num[i]!=9)
            {
                ans=f[i];
                break;
            }
        }
    }
    cout << ans << endl;
}
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t;
    f[0] = 1;
    for (int i = 1; i <= 18; i++)
        f[i] = f[i - 1] * 10;
    cin >> t;
    while (t--)
    {
        work();
    }
    return 0;
}