"""
출처:프로그래머스,
https://school.programmers.co.kr/learn/courses/30/lessons/17687
"""

# 풀이과정

def solution(n, t, m, p):
    from collections import deque
    check = m * t
    all_num = deque([0])
    count = 1

    while True:
        start = count
        num = deque([])

        while True:
            start, j = divmod(start, n)  # i 몫 j 나머지

            if start == 0:
                if j != 0:
                    if j == 10:
                        num.appendleft("A")
                    elif j == 11:
                        num.appendleft("B")
                    elif j == 12:
                        num.appendleft("C")
                    elif j == 13:
                        num.appendleft("D")
                    elif j == 14:
                        num.appendleft("E")
                    elif j == 15:
                        num.appendleft("F")
                    else:
                        num.appendleft(j)
                break
            else:
                if j == 10:
                    num.appendleft("A")
                elif j == 11:
                    num.appendleft("B")
                elif j == 12:
                    num.appendleft("C")
                elif j == 13:
                    num.appendleft("D")
                elif j == 14:
                    num.appendleft("E")
                elif j == 15:
                    num.appendleft("F")
                else:
                    num.appendleft(j)
        all_num += num
        if len(all_num) >= check:
            break

        count += 1

    all_num = "".join(list(map(str, list(all_num)[p - 1::m][0:t])))

    return all_num