#!/usr/bin/env python3
import math
import sys
input = lambda: sys.stdin.readline().rstrip("\r\n")
def test_case():
n, d, m = map(int, input().split())
jobs = []
cnt = [0 for _ in range(n+1)]
i = 1
for x in input().split():
jobs.append([int(x), i])
cnt[jobs[-1][0]] += 1
i += 1
jobs.sort()
# print(jobs)
def cond(x):
max_d = 0
j = 0
for i in range(1, n+1):
curr = 0
while j < m and curr < x and jobs[j][0] <= i:
# print(i, jobs[j])
max_d = max(max_d, i-jobs[j][0])
if max_d > d: return False
curr += 1
j += 1
# print(x, max_d)
# print("=======")
return True
def cond2(x):
req_num = 0
schedule = [[] for _ in range(n)]
for day in range(1, n+1):
for j in range(x):
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 discrete_binary_search(func, lo, hi):
""" Locate the first value x s.t. func(x) = True within [lo, hi] """
res = []
while lo < hi:
mi = lo + (hi - lo) // 2
res1, res2 = func(mi)
if res1:
hi = mi
res = res2
else:
lo = mi + 1
return lo, res
ans, res = discrete_binary_search(cond2, 1, m)
print(ans)
for i in range(n):
if len(res[i]) > 0:
print(*res[i], end=' ')
print(0)
else:
print(0)
def main():
t = 1
# t = int(input())
for _ in range(t):
test_case()
if __name__ == '__main__':
main()
