#include <iostream>

#include <vector>

#include <algorithm>

using namespace std;

int N, M, K;

int board[101][101];

bool visited[101][101];

int howmany = 0;

vector<int> area;

int dfs(int i, int j) {

int count = 1;

visited[i][j] = true;

if (i > 0 && board[i-1][j] == 0 && !visited[i - 1][j]) {

count += dfs(i - 1, j);

}

if (j > 0 && board[i][j - 1] == 0 && !visited[i][j - 1]) {

count += dfs(i, j - 1);

}

if (i < N - 1 && board[i + 1][j] == 0 && !visited[i + 1][j]) {

count += dfs(i + 1, j);

}

if (j < M - 1 && board[i][j + 1] == 0 && !visited[i][j + 1]) {

count += dfs(i, j + 1);

}

return count;

}

int main()

{

int i, j, k;

cin >> M >> N >> K;

for (i = 0; i < N; i++) {

for (j = 0; j < M; j++) {

board[i][j] = 0;

visited[i][j] = false;

}

}

for (k = 0; k < K; k++) {

int lx, ly, rx, ry;

cin >> lx >> ly >> rx >> ry;

for (i = lx; i < rx; i++) {

for (j = ly; j < ry; j++) {

board[i][j] = 1;

}

}

}

for (i = 0; i < N; i++) {

for (j = 0; j < M; j++) {

if (board[i][j] == 0 && !visited[i][j]) {

howmany++;

area.push_back(dfs(i, j));

}

}

}

cout << howmany << "\n";

sort(area.begin(), area.end());

for (i = 0; i < area.size(); i++) {

cout << area[i] << " ";

}

}