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 sg[3050][3050 * 2], fa[3050 * 3050 * 2], n, m, st, p, ans;
bool b[3050 * 3050 * 2];
const int dir[8][2] = {{0, 1}, {1, 0},  {-1, 0}, {0, -1},
                       {1, 1}, {1, -1}, {-1, 1}, {-1, -1}};
inline int Read() {
  int x = 0;
  char y;
  do y = getchar();
  while (y < '0' || y > '9');
  do x = x * 10 + y - '0', y = getchar();
  while (y >= '0' && y <= '9');
  return x;
}
int Find(int x) { return fa[x] == x ? x : (fa[x] = Find(fa[x])); }
int main() {
  n = Read();
  m = Read();
  p = Read();
  while (p--) {
    int k = Read(), l = Read();
    bool flag = false;
    for (int i = 0; i < 8; i++) {
      int q = k + dir[i][0], w = l + dir[i][1];
      if (sg[q][w]) b[Find(sg[q][w])] = true;
    }
    l += m;
    for (int i = 0; i < 8; i++) {
      int q = k + dir[i][0], w = l + dir[i][1];
      if (sg[q][w] && b[Find(sg[q][w])]) {
        flag = true;
        break;
      }
    }
    l -= m;
    if (flag)
      for (int i = 0; i < 8; i++) {
        int q = k + dir[i][0], w = l + dir[i][1];
        if (sg[q][w]) b[Find(sg[q][w])] = false;
      }
    else {
      sg[k][l] = ++st;
      fa[st] = st;
      sg[k][l + m] = ++st;
      fa[st] = st;
      for (int i = 0; i < 8; i++) {
        int q = k + dir[i][0], w = l + dir[i][1], e = l + m + dir[i][1];
        if (sg[q][w]) fa[Find(sg[q][w])] = st - 1;
        if (sg[q][e]) fa[Find(sg[q][e])] = st;
      }
    }
    ans += !flag;
  }
  cout << ans << endl;
  return 0;
}
