string s = to_string(r);
int n = s.size();
for (int i = 0; i <= n; i++)
    for (int j = 0; j < 10; j++)
        for (int k = 0; k < 10; k++)
            for (int l = 0; l < 2; l++) dp[i][j][k][l] = -1;
dp[0][0][9][1] = 0;
for (int i = 1; i <= n; i++){
    int dg = s[i-1] - '0';
    for (int j = 0; j <= dg; j++){
        for (int mx = 0; mx <= 9; mx++){
            for (int mn = 0; mn <= 9; mn++){
                if (dp[i-1][mx][mn][1] == -1) continue;
                dp[i][max(mx, j)][min(mn, j)][dg == j] = max(dp[i-1][mx][mn][1] * 10 + j, dp[i][max(mx, j)][min(mn, j)][dg == j]);
            }
        }
    }
    for (int j = 0; j <= 9; j++){
        for (int mx = 0; mx <= 9; mx++){
            for (int mn = 0; mn <= 9; mn++){
                if (dp[i-1][mx][mn][0] == -1) continue;
                dp[i][max(mx, j)][min(mn, j)][0] = max(dp[i-1][mx][mn][0] * 10 + j, dp[i][max(mx, j)][min(mn, j)][0]);
            }
        }
    }
}
vector <pair <int, int64> > v;
for (int i = 0; i < 10; i++){
    for (int j = 0; j <= i; j++){
        for (int t = 0; t < 2; t++){
            if (dp[n][i][j][t] != -1) {
                v.push_back({i-j, dp[n][i][j][t]});
            }
        }
    }
}
sort(v.begin(), v.end());
for (auto i: v) {
    if (i.second >= l) {
        cout << i.second << "\n";
        return;
    }
}