중복 제거 set함수 이용

def DFS(L):
    global res, cnt
    if L == m:
        if len(res) != len(set(res)):
            pass
        else:
            for i in res:
                print(i, end = ' ')
            print()
            cnt += 1
    else:
        for i in range(1, n+1):
            res[L] = i
            DFS(L+1)

if __name__ == "__main__":
    n, m = map(int, input().split())
    res = [0] * m
    cnt = 0
    DFS(0)
    print(cnt)