from typing import List, Tuple
N, D, M = 0, 0, 0
def is_feasible(jobs: List[Tuple[int, int]], machine_count: int) -> Tuple[bool, List[List[int]]]:
schedule = [[] for _ in range(N)]
req_num = 0
for day in range(1, N + 1):
for j in range(machine_count):
if jobs[req_num][0] > day:
break
if jobs[req_num][0] + D >= day:
schedule[day - 1].append(jobs[req_num][1])
req_num += 1
else:
return False, schedule
if req_num == M:
return True, schedule
return False, schedule
def main():
global N, D, M
import sys
input = sys.stdin.readline
N,D,M=map(int,input().split())
jobs = list(map(int,input().split()))
for i in range(M):
jobs[i]=(jobs[i],i+1)
jobs.sort()
result = []
l, r = 1, M
while l < r:
machine_num = (l + r) // 2
cur_result = is_feasible(jobs, machine_num)
if cur_result[0]:
r = machine_num
result = cur_result[1]
else:
l = machine_num + 1
print(l)
for i in range(N):
for idx in result[i]:
print(idx, end=" ")
print(0)
main()
