DSA02030.cpp

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <cstring>
#include <algorithm>
#include <queue>
#include <map>
#include <set>
#include <stack>
#include <cmath>
#include <iomanip>
#include <cstdlib>
#include <numeric>
#include <unordered_set>
using namespace std;

#define ll long long
// MAX (long long) 1000000000000000000
//#define M 100 + 5
#define N 200

//#define MOD (ll) 1000000007
#define ld long double
#define sz size()
#define FOR(i, a, b) for(int i = a; i <= b; i++)
#define FORD(i, a, b) for (int i = a; i >= b; i--)
#define faster() ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL);
#define zero(n) setw(n) << setfill('0')
#define stp(n) fixed << setprecision(n)

char c;
int k;

char x[100];

void in() {
	for (int i = 1; i <= k; i++) {
		cout << x[i];
	}
	cout << endl;
}

void Try(int i) {
	for (int ch = x[i - 1]; ch <= c; ch++) {
		x[i] = ch;
		if (i == k) in();
		else Try(i + 1);
	}
}

int main() {

	cin >> c >> k;

	x[0] = 'A';

	Try(1);

	return 0;
}