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, q, parenti[3005][6005], parentj[3005][6005], cnt[3005][6005], ans,
    col[3005];
bool square[3005][6005], f;
int mx[] = {0, -1, -1, -1, 0, 0, 1, 1, 1};
int my[] = {0, -1, 0, 1, -1, 1, -1, 0, 1};
pair<int, int> fnd(int x, int y) {
  if (parenti[x][y] == x && parentj[x][y] == y) return make_pair(x, y);
  pair<int, int> p = fnd(parenti[x][y], parentj[x][y]);
  parenti[x][y] = p.first;
  parentj[x][y] = p.second;
  return p;
}
inline void uion(int xa, int ya, int xb, int yb) {
  pair<int, int> roota = fnd(xa, ya);
  pair<int, int> rootb = fnd(xb, yb);
  xa = roota.first;
  ya = roota.second;
  xb = rootb.first;
  yb = rootb.second;
  if (xa == xb && ya == yb) return;
  parenti[xa][ya] = xb;
  parentj[xa][ya] = yb;
  cnt[xb][yb] += cnt[xa][ya];
}
int main() {
  cin >> n >> m >> q;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= 2 * m; j++) {
      parenti[i][j] = i;
      parentj[i][j] = j;
      cnt[i][j] = 1;
    }
  }
  for (int p = 1; p <= q; p++) {
    int x, y;
    cin >> x >> y;
    square[x][y] = true;
    square[x][y + m] = true;
    col[y]++;
    f = false;
    pair<int, int> tp = fnd(x, y);
    for (int i = 1; i <= 8; i++) {
      int tx = x + mx[i];
      int ty = y + my[i] + m;
      if (tx < 1 || tx > n || ty > 2 * m) continue;
      if (square[tx][ty]) {
        f = true;
        uion(x, y, tx, ty);
      }
    }
    if (!f) {
      ans++;
      continue;
    } else {
      f = false;
      for (int i = 1; i <= m; i++) {
        if (col[i] == 0) {
          f = true;
          break;
        }
      }
      if (f) {
        ans++;
        continue;
      } else {
        col[y]--;
        square[x][y] = false;
        square[x][y + m] = false;
        pair<int, int> p = fnd(x, y);
        cnt[p.first][p.second] -= cnt[tp.first][tp.second];
      }
    }
  }
  cout << ans;
  return 0;
}
