#include<bits/stdc++.h>
using namespace std;
using s64 = long long;
using i128 = __int128_t;
struct gao{
    vector<int> a;
    gao(int x = 0) {
        while(x) {
            a.push_back(x % 10);
            x /= 10;
        }
        if(a.empty()) a.resize(1, 0);
    }
    gao(s64 x) {
        while(x) {
            a.push_back(x % 10);
            x /= 10;
        }
        if(a.empty()) a.resize(1, 0);
    }
    gao(string_view s) {
        for(auto it = s.rbegin(); it != s.rend(); it++) {
            a.push_back((*it) - '0');
        }
        if(a.empty()) a.resize(1, 0);
    }
    gao& operator+=(const gao& A) {
        // vector<int> tmp(max(a.size(), A.a.size()), 0);
        a.resize(max(a.size(), A.a.size()) + 2, 0);
        for(int i = 0; i + 1 < (int)a.size(); i++) {
            if(i < (int)A.a.size())
                a[i] += A.a[i];
            else if(A.a[i] < 10) break;
            if(a[i] >= 10) {
                a[i + 1]++;
                a[i] -= 10;
            }
        }
        while(a.size() > 1 && a.back() == 0) {
            a.pop_back();
        }
        return *this;
    }
    gao operator+(const gao& A) {
        auto tmp = *this;
        return tmp += A;
    }
    i128 subint(int l, int r) {
        i128 now = 0;
        for(r = min(r, (int)a.size() - 1); r >= l; r--)
            now = now * 10 + a[r];
        return now;
    }
    friend istream& operator>>(istream& is, gao& A) {
        static string tmp;
        cin >> tmp;
        A = gao(tmp);
        return is;
    }
    friend ostream& operator<<(ostream& os, const gao& A) {
        for(auto it = A.a.rbegin(); it != A.a.rend(); it++)
            os << (*it);
        return os;
    }
}n;
bool find(const gao& n, s64 m) {
    s64 M = m, now = 0, rt = 1;
    int len = 0;
    while(m) {
        m /= 10;
        len++;
    }
    len = max(1, len);
    if(n.a.size() < len) return false;
    for(int i = len - 1; i >= 0; i--)
        now = now * 10 + n.a[i], rt *= 10;
    rt /= 10;
    if(now == M) return true;
    for(int i = len; i < n.a.size(); i++) {
        now = now / 10 + rt * n.a[i];
        if(now == M) return true;
    }
    return false;
}
s64 m;
s64 Ans;
int lenm = 0;
void solve() {
    cin >> n >> m;
    lenm = 0;
    n += 1;
    {
        s64 tmpm = m;
        while(tmpm) {
            tmpm /= 10;
            lenm++;
        }
        if(lenm == 0) lenm = 1;
    }
    if(find(n, m)) {
        cout << n << '\n';
        return;
    }
    Ans = 0;
    for(int i = (int)n.a.size() - 1; i >= 0; i--) {
        Ans = (Ans * 10 + n.a[i]) % m;
    }
    if(Ans != 0) Ans = m - Ans;
    {
        s64 now = 0;
        for(int i = min((int)n.a.size(), lenm - 1); i >= 0; i--) {
            now = now * 10 + (9 - n.a[i]);
        }
        now++;
        if(find(n + now, m)) {
            Ans = min(Ans, now);
        }
    }
    i128 rt = 1;
    for(int i = 0; i <= 10; i++) {
        i128 tmp = n.subint(0, lenm + i - 1);
        // cerr << (s64)tmp << '\n';
        // cerr << (s64)(m * rt - tmp) << '\n';
        if(tmp <= rt * m && m * rt - tmp < Ans) {
            Ans = m * rt - tmp;
        }
        rt *= 10;

    }
    cout << n + Ans << '\n';

}
signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T;
    cin >> T;
    while(T--) {
        solve();
    }
}