#include <iostream>
#include <vector>
#include <algorithm>
#include <stdio.h>
#include <stdlib.h>
using namespace std;


int main() {
    string s;
    cin >> s;

    int n;
    cin >> n;

    string a[n];

    bool ok = true;
    for(int i = 0; i < n; i++) {
        cin >> a[i];

        if(s == a[i]) {
            ok = false;
        }
    }

    if(ok) {
        cout << s << endl;
        return 0;
    }

    for(int i = 1; i <= 201; i++) {
        string str = "";
        int x = i;
        while(x > 0) {
            str += (x % 10) + '0';
            x /= 10;
        }
        reverse(str.begin(), str.end());

        string tmp = s + str;

        bool moze = true;
        for(int j = 0; j < n; j++) {
            if(tmp == a[j]) {
                moze = false;
            }
        }

        if(moze) {
            cout << tmp << endl;
            break;
        }

    }

    return 0;
}

/// YNYYYNYNY