#include <iostream>
using namespace std;

void out(int n, string prefix = "")
{
    char last = prefix.size() ? prefix[prefix.size()-1] : 0;
    if (n == 1)
    {
        if (last != '1') cout << prefix << '1' << endl;
        cout << prefix << '0' << endl;
        return;
    }
    if (last != '1')
        out(n-1,prefix+"1");
    out(n-1,prefix+"0");
}


int main(int argc, char * argv[])
{
    int n = 10;
    out(n);
}