// compile: g++ -o data data.cpp -std=gnu++20
// run: ./data < data.in
#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define int long long

using namespace std;

int get_lucky(int x) {
    int minv = 11, maxv = -1;
    for (; x; x /= 10) {
        minv = min(minv, x % 10);
        maxv = max(maxv, x % 10);
    }
    return maxv - minv;
}

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int _; cin >> _;
    while (_--) {
        int l, r;
        cin >> l >> r;
        int maxv = -1, maxind = 0;
        for (int i = l; i <= r; ++i) {
            if (get_lucky(i) > maxv) {
                maxv = get_lucky(i);
                maxind = i;
            }
            if (maxv == 9) break;
        }
        cout << maxind << endl;
    }

    return 0;
}