#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int number = 0, k;
char *buff;

void nextStep(int step);

void printBuff();

int main() {
    printf("How many buffalos?");
    scanf("%d", &number);
    printf("How many k buffalos?");
    scanf("%d", &k);
    buff = (char *) malloc((number + k) * sizeof(char));
    memset(buff, 0, (number + k) * sizeof(char));
    nextStep(0);
    return 0;
}

void nextStep(int step) {

    if (step == number) {
        int j;
        for (j = 0; j < number; j++) {
            for (int i = 1; i < k+1; ++i) {
                if (buff[j] == 'D' && buff[j + i] == 'D')
                    return;
            }
        }
        printBuff();
    } else {
        buff[step] = 'D';
        nextStep(step + 1);
        buff[step] = 'C';
        nextStep(step + 1);
    }
}

void printBuff() {
    printf("%s\n", buff);
}