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;
const int dx[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
const int dy[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
int n, m, q, num, x, y, nx, ny, k, res, a[3003][6006], p[600300];
vector<int> v;
int fs(int i) {
  if (p[i] == i || p[i] == num) return i;
  return p[i] = fs(p[i]);
}
void un(int y) {
  int x = num;
  v.push_back(y);
  p[y] = x;
}
int main() {
  scanf("%d%d%d", &n, &m, &q);
  m *= 2;
  while (q--) {
    scanf("%d%d", &x, &y);
    a[x][--y] = ++num;
    p[num] = num;
    v.clear();
    for (k = 0; k < 8; k++) {
      nx = x + dx[k];
      if (nx < 1 || nx > n) continue;
      ny = (y + dy[k] + m) % m;
      if (a[nx][ny]) un(p[fs(a[nx][ny])]);
    }
    for (k = 0; k < 8; k++) {
      nx = x + dx[k];
      if (nx < 1 || nx > n) continue;
      ny = (y + m / 2 + dy[k] + m) % m;
      if (a[nx][ny] && p[fs(a[nx][ny])] == num) break;
    }
    if (k < 8) {
      a[x][y] = 0;
      for (k = 0; k < v.size(); k++) p[v[k]] = v[k];
    } else {
      a[x][y + m / 2] = ++num;
      p[num] = num;
      for (k = 0; k < 8; k++) {
        nx = x + dx[k];
        if (nx < 1 || nx > n) continue;
        ny = (y + m / 2 + dy[k] + m) % m;
        if (a[nx][ny]) un(p[fs(a[nx][ny])]);
      }
      res++;
    }
  }
  printf("%d\n", res);
  return 0;
}
