#include <stdio.h>

#include <string.h>

#define SIZE 100

int n, m, p, count;

int a[SIZE][SIZE];

void colour(int x, int y) {

count++;

a[x][y] = 1;

if ((x > 1) && (a[x - 1][y] == 0))

colour(x - 1, y);

if ((y > 1) && (a[x][y - 1] == 0))

colour(x, y - 1);

if ((x < n) && (a[x + 1][y] == 0))

colour(x + 1, y);

if ((y < m) && (a[x][y + 1] == 0))

colour(x, y + 1);

}

int main() {

int i, j, x, y, ans;

memset(a, 0, sizeof(a));

scanf("%d%d%d", &n, &m, &p);

for (i = 1; i <= p; i++) {

scanf("%d%d", &x, &y);

a[x][y] = 1;

}

ans = 0;

for (i = 1; i <= n; i++)

for (j = 1; j <= m; j++)

if (a[i][j] == 0) {

count = 0;

colour(i, j);

if (ans < count)

ans = count;

}

printf("%d\n", ans);

return 0;

}

输入：

6 5 9

1 4

2 3

2 4

3 2

4 1

4 3

4 5

5 4

6 4

输出：_________