// Hallelujah, praise the one who set me free
// Hallelujah, death has lost its grip on me
// You have broken every chain, There's salvation in your name
// Jesus Christ, my living hope
#include <bits/stdc++.h> 
using namespace std;

#define REP(i, s, e) for (int i = (s); i < (e); i++)
#define RREP(i, s, e) for (int i = (s); i >= (e); i--)
template <class T>
inline bool mnto(T& a, T b) {return b < a ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define SZ(_a) (int) _a.size()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef vector<iii> viii;

#ifndef DEBUG
#define cerr if (0) cerr
#endif

const int INF = 1000000005;
const ll LINF = 1000000000000000005ll;
const int MAXN = 200005;

int t;
string sn, sm;
int m;

int main() {
#ifndef DEBUG
    ios::sync_with_stdio(0), cin.tie(0);
#endif
    cin >> t;
    while (t--) {
        cin >> sn >> m;
        sn = "0" + sn;
        while (SZ(sn) <= 30) {
            sn = "0" + sn;
        }
        RREP (j, SZ(sn) - 1, 0) {
            if (sn[j] < '9') {
                sn[j]++;
                break;
            } else {
                sn[j] = '0';
            }
        }
        sm = to_string(m);
        bool perfect = 0;
        ll remain = 0;
        REP (i, 0, SZ(sn) - SZ(sm) + 1) {
            remain = (remain * 10 + (sn[i] - '0')) % m;
            bool same = 1;
            REP (j, 0, SZ(sm)) {
                if (sn[i + j] != sm[j]) {
                    same = 0;
                    break;
                }
            }
            if (same) {
                perfect = 1;
                break;
            }
        }
        string ans;
        if (perfect || remain == 0) {
            ans = sn;
        } else {
            ans = sn;
            ans[0] = '9';
            RREP (i, SZ(sn) - SZ(sm), SZ(sn) - 2 * SZ(sm) - 5) {
                string t = sn;
                REP (j, 0, SZ(sm)) {
                    t[i + j] = sm[j];
                }
                if (t < sn) {
                    RREP (j, i - 1, 0) {
                        if (t[j] < '9') {
                            t[j]++;
                            break;
                        } else {
                            t[j] = '0';
                        }
                    }
                }
                REP (j, i + SZ(sm), SZ(sn)) {
                    t[j] = '0';
                }
                mnto(ans, t);
            }
            string t = sn;
            remain = m - remain;
            REP (_, 0, SZ(sm)) {
                int d = remain % 10;
                RREP (i, SZ(sn) - 1, 0) {
                    int nd = t[i] - '0' + d;
                    t[i] = nd % 10 + '0';
                    d = nd / 10;
                    if (d == 0) {
                        break;
                    }
                }
                remain /= 10;
                if (remain == 0) {
                    break;
                }
            }
            mnto(ans, t);
        }
        bool zero = 1;
        REP (i, 0, SZ(ans)) {
            if (zero && ans[i] == '0') {
                continue;
            }
            zero = 0;
            cout << ans[i];
        }
        cout << '\n';
    }
    return 0;
}