#define _USE_MATH_DEFINES
#include<stdio.h>
#include<iostream>
#include<vector>
#include<cmath>
#include<algorithm>
#include<map>
#include<set>
#include<sstream>
#include<cstring>
#include<numeric>
#include<limits.h>
#include<time.h>
using namespace std;


vector<int> str;


set<int> was;

int getLast() {
    int res = 0;
    for (int i = str.size() - 4; i < str.size(); i++) {
        res *= 10;
        res += str[i];
    }
    return res;
}

int main() {
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
#endif

    freopen("output.txt", "w", stdout);

    srand(time(0));
    for (int i = 0; i < 4; i++) {
        str.push_back(rand() % 10);
    }

    was.insert(getLast());

    while (was.size() != 10000) {
        bool ok = false;
        for (int i = 0; i < 10; i++) {
            str.push_back(i);
            int val = getLast();
            if (was.count(val) != 0) {
                str.pop_back();
            }
            else {
                ok = true;
                break;
            }
        }
        if (!ok) {
            str.push_back(rand() % 10);
        }
    }

    printf("%d\n", str.size());
    for (auto i : str) {
        printf("%d", str[i]);
    }

    return 0;
}