alternator

#include<bits/stdc++.h>
using namespace std;
///****************
//THE ALTERNATOR
#define NMAX 23
int n, k, st[NMAX];
bitset<NMAX> bs;

void doDaOps() {
    for (int i = 1; i <= k; i++)
        bs[st[i]] = true;
    cout << bs << endl;
    bs = 0;
}

void backTr(int k) {
    if (k - 1 == ::k) {
        doDaOps();
        return;
    }
    for (int i = st[k - 1] + 1; i <= n; i++) {
        st[k] = i;
        backTr(k + 1);
    }
}

int main() {
    cin >> n >> k;
    assert(n < NMAX - 2 && n >= k);
    backTr(1);
    return 0;
}