import sys

sys.setrecursionlimit(100000)

# 2583

# call by value Tlqkf Tlqkf....

def dfs(i, j, area, dfs_map):

if i < 0 or i >= len(dfs_map) or \

j < 0 or j >= len(dfs_map[0]) or \

dfs_map[i][j] == False:

return

#visited

dfs_map[i][j] = False

area[0] += 1

dfs(i+1, j, area, dfs_map)

dfs(i-1, j, area, dfs_map)

dfs(i, j+1, area, dfs_map)

dfs(i, j-1, area, dfs_map)

#input

M, N, K = map(int, input().split())

points = []

#output

counts = 0

answ = []

#2차원 배열 입력

for _ in range(K):

points.append(list(map(int, input().split())))

# 머릿속으로는 초기화 하는 동시에 조건문으로 순환을 돌아야 할 T/F 나뉘는 2D배열을 초기화시키고 싶다.

dfs_map = [[True for _ in range(N)] for _ in range(M)]

#후보군 줄이기..? O(n^3)

for k in range(K):

for i in range(M):

for j in range(N):

if (i >= points[k][1] and i+1 <= points[k][3]) and \

(j >= points[k][0] and j+1 <= points[k][2]):

dfs_map[i][j] = False

for i in range(M):

for j in range(N):

if dfs_map[i][j] == True:

area = [0]

counts += 1

dfs(i, j, area, dfs_map)

answ.append(area[0])

answ.sort()

print(counts)

for i in answ:

print("{0} ".format(i), end='')

# 파일 입출력 ver.

# with open("./input.txt", "r") as f:

# M, N, K = map(int, f.readline().split())

# #2차원 배열 입력

# for _ in range(K):

# points.append(list(map(int, f.readline().split())))

# # 머릿속으로는 초기화 하는 동시에 조건문으로 순환을 돌아야 할 0/1 나뉘는 배열을 초기화시키고 싶다.

# dfs_map = [[True for _ in range(N)] for _ in range(M)]

# #후보군 줄이기..? n^3 홀리 쓍\ㅅ

# for k in range(K):

# for i in range(M):

# for j in range(N):

# if (i >= points[k][1] and i+1 <= points[k][3]) and \

# (j >= points[k][0] and j+1 <= points[k][2]):

# dfs_map[i][j] = False

# for i in range(M):

# for j in range(N):

# if dfs_map[i][j] == True:

# area = [0]

# counts += 1

# dfs(i, j, area, dfs_map)

# answ.append(area[0])

# answ.sort()

# print(counts)

# for i in answ:

# print("{0} ".format(i), end='')

#input

# M, N, K = map(int, input().split())

# for _ in range(K):

# points.append(list(map(int, input().split())))