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 id[3001][6001], par[300001], cnt;
int fnd(int k) { return par[k] == k ? k : par[k] = fnd(par[k]); }
constexpr int dx[] = {-1, -1, -1, 0, 0, 1, 1, 1, 0},
              dy[] = {-1, 0, 1, -1, 1, -1, 0, 1, 0};
int n, m;
vector<int> neighbor(int x, int y) {
  vector<int> ret;
  for (int dx = -1; dx <= 1; ++dx) {
    int ox = x + dx;
    if (ox > 0 && ox <= n)
      for (int dy = -1; dy <= 1; ++dy) {
        int oy = y + dy;
        if (oy > 0 && oy <= 2 * m && id[ox][oy] != -1)
          ret.push_back(id[ox][oy]);
      }
  }
  return ret;
}
void mark(int x, int y) {
  id[x][y] = ++cnt;
  par[cnt] = cnt;
  auto v = neighbor(x, y);
  for (auto c : v) par[fnd(c)] = cnt;
}
bool can_mark(int x, int y) {
  auto v1 = neighbor(x, y), v2 = neighbor(x, m + y);
  for (auto c1 : v1)
    for (auto c2 : v2)
      if (fnd(c1) == fnd(c2)) return false;
  return true;
}
int main() {
  int q, ans = 0;
  scanf("%d%d%d", &n, &m, &q);
  if (m == 1) {
    printf("0\n");
    return 0;
  }
  memset(id, -1, sizeof(id));
  while (q--) {
    int t1, t2;
    scanf("%d%d", &t1, &t2);
    if (can_mark(t1, t2)) {
      ++ans;
      mark(t1, t2);
      mark(t1, t2 + m);
    }
  }
  printf("%d\n", ans);
  return 0;
}
