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 maxn = 7030;
const int mod = 1e9 + 7;
int dx[] = {1, 1, 1, -1, -1, -1, 0, 0};
int dy[] = {0, 1, -1, 0, 1, -1, 1, -1};
int n, m, q, par[3010 * maxn + 6030];
bool vis[3010 * maxn + 6030];
int root(int v) { return v == par[v] ? v : par[v] = root(par[v]); }
void unite(int first, int second, int xx, int yy) {
  int a = first * maxn + second, b = xx * maxn + yy;
  if ((a = root(a)) == (b = root(b))) return;
  par[a] = b;
}
int main() {
  ios_base::sync_with_stdio(false), cin.tie(0);
  cin >> n >> m >> q;
  if (m == 1) return cout << "0\n", 0;
  for (int i = 1; i < 3010 * maxn + 6030; i++) par[i] = i;
  int ans = 0;
  while (q--) {
    int r, c;
    cin >> r >> c;
    bool bad = false;
    set<int> s;
    for (int d = 0; d < 8; d++) {
      int first = r + dx[d], second = c + m + dy[d];
      if (vis[first * maxn + second]) s.insert(root(first * maxn + second));
    }
    for (int d = 0; d < 8; d++) {
      int first = r + dx[d], second = c + dy[d];
      if (vis[first * maxn + second]) {
        if (s.count(root(first * maxn + second))) bad = true;
      }
    }
    if (bad) continue;
    vis[r * maxn + c] = true;
    vis[r * maxn + c + m] = true;
    ++ans;
    for (int d = 0; d < 8; d++) {
      int first = r + dx[d], second = c + dy[d];
      if (vis[first * maxn + second]) unite(r, c, first, second);
    }
    for (int d = 0; d < 8; d++) {
      int first = r + dx[d], second = c + m + dy[d];
      if (vis[first * maxn + second]) unite(r, c + m, first, second);
    }
  }
  cout << ans << "\n";
  return 0;
}
