2 5 10
2 2
1 1
1 4
2 1
1 2
1 5
2 4
2 5
1 3
2 3
 2 2 2
1 1
2 2
 3 3 9
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3
 7 5 35
5 3
3 5
1 1
2 5
6 4
7 2
5 1
3 4
6 5
7 3
4 1
2 2
4 2
2 4
4 3
3 3
6 1
1 2
4 5
1 3
2 1
5 5
7 5
7 1
6 2
1 4
1 5
3 2
4 4
5 2
2 3
6 3
7 4
5 4
3 1
 1 5 4
1 1
1 2
1 4
1 5
 1 1 1
1 1
 5 7 21
4 4
4 5
5 5
5 6
5 7
5 1
5 2
4 2
3 2
3 1
3 7
3 6
2 6
1 6
1 7
1 1
1 2
1 3
1 4
2 4
3 4
 2 1 1
1 1
 2 2 4
2 1
1 1
1 2
2 2
 3000 3000 1
2222 738
 5 7 35
1 2
2 3
5 1
5 7
4 4
5 3
3 1
2 6
4 5
2 7
4 1
2 1
2 2
1 7
5 6
3 6
4 6
1 6
1 1
3 3
3 4
4 2
2 5
5 5
3 5
2 4
1 5
1 3
4 3
5 4
1 4
3 7
4 7
3 2
5 2
 5 4 1
4 1
 3 4 12
2 3
3 2
2 2
2 1
1 2
3 1
1 4
1 3
3 3
2 4
3 4
1 1
 3 3 3
1 1
2 2
3 3

8
 1
 6
 26
 4
 0
 20
 0
 2
 1
 28
 1
 9
 3

#include <bits/stdc++.h>
using namespace std;
int n, m, col, nq, ans;
int fa[20000010], used[20000010], a[3010][6010],
    v[8][2] = {-1, -1, -1, 0, -1, 1, 0, -1, 0, 1, 1, -1, 1, 0, 1, 1};
int find(int i) { return fa[i] == i ? i : fa[i] = find(fa[i]); }
void connect(int x, int y) {
  int fx, fy;
  fx = find(x);
  fy = find(y);
  if (fx != fy) fa[fx] = fy;
}
int main() {
  int i, j, x, y, nx, ny, flag;
  scanf("%d%d%d", &n, &m, &nq);
  m *= 2;
  for (i = 1; i <= n; i++)
    for (j = 1; j <= m; j++) fa[((i - 1) * m + j)] = ((i - 1) * m + j);
  for (i = 1; i <= nq; i++) {
    scanf("%d%d", &x, &y);
    col++;
    for (j = 0; j <= 7; j++) {
      nx = x + v[j][0];
      ny = (y + v[j][1] + m - 1) % m + 1;
      if (nx > n || nx < 1 || ny > m || ny < 1 || a[nx][ny] == 0) continue;
      used[find(((nx - 1) * m + ny))] = col;
    }
    flag = 0;
    for (j = 0; j <= 7; j++) {
      nx = x + v[j][0];
      ny = (y + m / 2 + v[j][1] + m - 1) % m + 1;
      if (nx > n || nx < 1 || ny > m || ny < 1 || a[nx][ny] == 0) continue;
      if (used[find(((nx - 1) * m + ny))] == col) flag = 1;
    }
    if (flag == 0 && m > 2) {
      ans++;
      for (j = 0; j <= 7; j++) {
        nx = x + v[j][0];
        ny = (y + v[j][1] + m - 1) % m + 1;
        if (nx > n || nx < 1 || ny > m || ny < 1 || a[nx][ny] == 0) continue;
        connect(((nx - 1) * m + ny), ((x - 1) * m + y));
      }
      for (j = 0; j <= 7; j++) {
        nx = x + v[j][0];
        ny = (y + m / 2 + v[j][1] + m - 1) % m + 1;
        if (nx > n || nx < 1 || ny > m || ny < 1 || a[nx][ny] == 0) continue;
        connect(((nx - 1) * m + ny), ((x - 1) * m + y + m / 2));
      }
      a[x][y] = 1;
      a[x][y + m / 2] = 1;
    }
  }
  printf("%d\n", ans);
  return 0;
}
