#include<iostream>
#include<cstdio>
#include<algorithm>
#include<string>
#include<cstring>
#include<cmath>
#include<set>
#include<map>
#include<vector>
#include<queue>
#include<unordered_map>
#include<stack>
#include<numeric>
using namespace std;
#define int long long
const int INF = 0X3f3f3f3f3f3f3f3f;

#define rep(i, a, b) for(int i = a;i <= b;i++)
#define pre(i, a, b) for(int i = a;i >= b;i--)

int x, m;
int dp[20][20][2];
int num[20];
int a[20];

void solve()
{
    memset(dp, 0x3f, sizeof dp);
    memset(a, 0, sizeof a);
    int cnt = 0;
    while (x)
    {
        a[++cnt] = x % 10;
        x /= 10;
    }
    num[0] = 1;
    rep(i, 1, 18) num[i] = num[i - 1] * 10;
    dp[0][0][0] = 0;
    int p = max(cnt, m);
    if (m == 0)
    {
        rep(i, 1, cnt + 1)
        {
            if (a[i] != 9) {
                cout << num[i - 1] << endl;
                return;
            }
        }
    }
    rep(i, 1, 18)
    {
        rep(k, 0, m)
        {
            if (a[i] + 1 < 10)
            {
                dp[i][k][0] = min(dp[i - 1][k][1], dp[i - 1][k][0]);
            }
            else
            {
                dp[i][k][0] = dp[i - 1][k][0];
            }
            if (k != 0)
            {
                if (a[i] != 0) dp[i][k][1] = min((10 - a[i] - 1) * num[i - 1] + dp[i - 1][k - 1][1], (10 - a[i]) * num[i - 1] + dp[i - 1][k - 1][0]);
                else dp[i][k][1] = (10 - a[i] - 1) * num[i - 1] + dp[i - 1][k - 1][1];
            }
        }
    }
    int ans = INF;
    rep(i, cnt, 18) {
        ans = min(ans, min(dp[i][m][1], dp[i][m][0]));
    }
    cout << ans << endl;
    return;
}

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