#include <iostream>
#include <vector>
using namespace std;
bool checkPrime(int x){
    for (int i = 3; (i*i) <= x; i+=2){
        if (x%i == 0){
            return false;
        }
    }
    return true;
}
int main(){
    vector<int>a[7];
// i think im allowed to have precomputed 1 digit primes right?
    a[0].push_back(2);
    a[0].push_back(3);
    a[0].push_back(5);
    a[0].push_back(7);
    cout << 7 << "\n";
    for (int i = 1; i < 7; ++i){
        for (int x = 0; x < a[i-1].size(); ++x){
            for (int j = 1; j <= 9; j+=2){
                int temp = a[i-1][x] * 10 + j;
                if (checkPrime(temp)){
                    a[i].push_back(temp);
                }
            }
        }
        cout << a[i][a[i].size() - 1] << "\n";
    }
}