// compile: g++ -o data data.cpp -std=gnu++20 -DLOCAL
// run: ./data < data.in
#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#ifdef LOCAL
#endif
#define sz(v) ((int)(v).size())
#define PV(v) for (int i=0;i<v.size();++i)cout<<v[i]<<" ";cout<<endl;
#define int long long

using namespace std;

vector<int> L, R, lst;
int len, minans = 11;

void to_vector(int x, vector<int> &v) {
    v.clear();
    for (; x; x /= 10) v.push_back(x % 10);
    reverse(v.begin(), v.end());
}

bool less_than(vector<int> &a, vector<int> &b) {
    if (sz(a) < sz(b)) return 1;
    else if (sz(a) > sz(b)) return 0;
    for (int i = 0; i < sz(a); ++i) {
        if (a[i] < b[i]) return 1;
        else if (a[i] > b[i]) return 0;
    }
    return 1;
}

bool greater_than(vector<int> &a, vector<int> &b) {
    if (sz(a) > sz(b)) return 1;
    else if (sz(a) < sz(b)) return 0;
    for (int i = 0; i < sz(a); ++i) {
        if (a[i] > b[i]) return 1;
        else if (a[i] < b[i]) return 0;
    }
    return 1;
}

void check(vector<int> &v) {
    if (!greater_than(v, L) || !less_than(v, R)) return;
    int minv = 11, maxv = -1;
    for (auto it = v.begin(); it!= v.end(); ++it) {
        minv = min(minv, *it);
        maxv = max(maxv, *it);
    }
    if (maxv - minv < minans) {
        minans = maxv - minv;
        lst = v;
    }
}

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int _; cin >> _;
    while (_--) {
        minans = 11;
        int l, r; cin >> l >> r;
        to_vector(l, L); to_vector(r, R);
        if (sz(R) > sz(L)) {
            for (int i = 0; i < sz(L); ++i) cout << 9;
            cout << endl;
            continue;
        }
        len = sz(L);
        vector<int> ans(len, -1);
        int p = 0;
        for (; p < len && L[p] == R[p]; ++p) ans[p] = L[p];
        int remain = len - p;
        for (int i = 0; i <= remain; ++i) {
            int j;
            for (j = p; j < p + i; ++j) ans[j] = L[j];
            for (int k = 0; k < 10; ++k) {
                for (int q = j; q < len; ++q) ans[q] = k;
                check(ans);
            }
            for (j = p; j < p + i; ++j) ans[j] = R[j];
            for (int k = 0; k < 10; ++k) {
                for (int q = j; q < len; ++q) ans[q] = k;
                check(ans);
            }
        }
        for (int i = 0 ; i < sz(lst); ++i) cout << lst[i];
        cout << endl;
    }

    return 0;
}