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>
const int L = 3e3;
const int N = 3e5;
int r, c, n;
bool filled[L + 1][L + 1];
class DisjointSet {
 public:
  static const int NODE = L * L;
  int fa_[NODE + 1];
  inline void init(int u) { fa_[u] = u; }
  int find(int u) { return fa_[u] == u ? u : fa_[u] = find(fa_[u]); }
  inline void merge(int u, int v) {
    u = find(u), v = find(v);
    fa_[u] = v;
  }
  bool connect(int u, int v) {
    u = find(u), v = find(v);
    return u == v;
  }
} s;
inline int id(int x, int y) { return (x - 1) * c + y; }
void work() {
  scanf("%d%d%d", &r, &c, &n);
  for (int i = 1; i <= r * c; ++i) s.init(i);
  int ans = 0;
  for (int i = 1; i <= n; ++i) {
    int x, y;
    scanf("%d%d", &x, &y);
    int px = x - 1, nx = x + 1;
    int py = y - 1, ny = y + 1;
    if (py == 0) py = c;
    if (ny == c + 1) ny = 1;
    if (px == 0) px = 1;
    if (nx == r + 1) nx = r;
    bool flag = false;
    for (int j = px; j <= nx && !flag; ++j)
      for (int k = px; k <= nx && !flag; ++k)
        if (filled[j][py] && filled[k][ny] && s.connect(id(j, py), id(k, ny)))
          flag = true;
    if (flag) continue;
    ++ans;
    filled[x][y] = true;
    for (int j = px; j <= nx; ++j) {
      if (filled[j][py]) s.merge(id(j, py), id(x, y));
      if (filled[j][ny]) s.merge(id(j, ny), id(x, y));
    }
  }
  printf("%d\n", ans);
}
int main() {
  work();
  return 0;
}
