87.cpp

#include <iostream>
#include <cmath>
#include <cstdio>

using namespace std;

int n, k;
int ar[101] = {};

void f(int cur);
void print();

int main(){

    cin >> n >> k;
    f(0);
    return 0;
}

void f(int cur){
    if (cur == k){
        print();
        return;
    }
    if (cur == 0){
        for (int i = 1; i <= n - k + 1; i++){
            ar[cur] = i;
            f(cur + 1);
        }
    }else{
        for (int i = ar[cur - 1] + 1; i <= n - (k - cur) + 1; i++){
            ar[cur] = i;
            f(cur + 1);
        }
    }
}

void print(){
    for (int i = 0; i < k; i++)
        cout << ar[i] << " ";
    cout << endl;
}