import sys
def main():
input = sys.stdin.readline
N, D, M = map(int, input().split())
S = list(map(int, input().split()))
# jobs: (arrival_day, id)
jobs = [(S[i], i + 1) for i in range(M)]
jobs.sort() # sort by arrival day (also deadline order)
# Feasibility check for given K; if build=True, also returns a schedule
def simulate(K: int, build: bool = False):
req = 0 # pointer to next unscheduled job in "jobs"
schedule = [[] for _ in range(N)] if build else None
# Simulate days 1..N
for day in range(1, N + 1):
used = 0
# Try to schedule up to K jobs today, in arrival order,
# but only those that have arrived (jobs[req][0] <= day).
while used < K and req < M and jobs[req][0] <= day:
s, jid = jobs[req]
# If this job's deadline already passed, infeasible
if s + D < day:
return False, None
if build:
schedule[day - 1].append(jid)
req += 1
used += 1
# (If the next job hasn't arrived yet, we just leave machines idle today.)
# After day N, all jobs must be scheduled
if req == M:
return True, schedule
return False, None
# Binary search the minimal K
lo, hi = 1, M
best_sched = None
while lo < hi:
mid = (lo + hi) // 2
ok, _ = simulate(mid, build=False)
if ok:
hi = mid
else:
lo = mid + 1
# Build schedule for minimal K
_, best_sched = simulate(lo, build=True)
# Output
print(lo)
for day in range(N):
if best_sched[day]:
print(*best_sched[day], 0)
else:
print(0)
if __name__ == "__main__":
main()
