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 delx[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
const int dely[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
map<pair<int, int>, int> appear;
vector<pair<int, int> > e[100010];
bitset<3010> g[100010];
int p[100010], exist[100010], dx[100010], dy[100010];
int find(int x) {
  if (p[x] == x) return x;
  p[x] = find(p[x]);
  return p[x];
}
void merge(int x, int y) {
  x = find(x);
  y = find(y);
  if (x == y) return;
  p[x] = y;
  g[y] |= g[x];
}
void lemon() {
  int n, m, s;
  scanf("%d%d%d", &n, &m, &s);
  for (int i = (1); i <= (s); i++) {
    scanf("%d%d", &dx[i], &dy[i]);
    appear[make_pair(dx[i], dy[i])] = i;
  }
  for (int i = (1); i <= (s); i++)
    for (int dir = (0); dir <= (7); dir++) {
      int x = dx[i] + delx[dir], y = dy[i] + dely[dir];
      if (x < 1 || x > n) continue;
      if (y > m) y -= m;
      if (y < 1) y += m;
      if (appear.count(make_pair(x, y)) && appear[make_pair(x, y)] < i) {
        int t = -1;
        if (dely[dir] == -1)
          t = y;
        else if (dely[dir] == 1)
          t = dy[i];
        e[i].push_back(make_pair(appear[make_pair(x, y)], t));
      }
    }
  int answer = 0;
  for (int i = (1); i <= (s); i++) p[i] = i;
  memset(exist, 0, sizeof exist);
  for (int i = (1); i <= (s); i++) {
    bitset<3010> t;
    for (typeof((e[i]).begin()) it = (e[i]).begin(); it != (e[i]).end(); it++)
      if (exist[it->first]) {
        t |= g[find(it->first)];
        if (it->second != -1) t[it->second] = 1;
      }
    if (t.count() == m) continue;
    answer++;
    exist[i] = 1;
    for (typeof((e[i]).begin()) it = (e[i]).begin(); it != (e[i]).end(); it++)
      if (exist[it->first]) {
        merge(i, it->first);
        if (it->second != -1) g[find(i)][it->second] = 1;
      }
  }
  cout << answer << endl;
}
int main() {
  ios::sync_with_stdio(true);
  lemon();
  return 0;
}
