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 bh[3030][6030];
int dsu[605050];
int r, c, n, k = 0, ans = 0;
int find(int x) { return x == dsu[x] ? x : dsu[x] = find(dsu[x]); }
void init() {
  int i, j;
  scanf("%d %d %d", &r, &c, &n);
}
int dx[8] = {-1, -1, -1, 0, 1, 1, 1, 0};
int dy[8] = {-1, 0, 1, 1, 1, 0, -1, -1};
void reclamation(int x, int y) {
  int i, j, ix, iy, jx, jy;
  set<int> S1, S2;
  for (i = 0; i < 8; i++) {
    ix = x + dx[i];
    iy = y + dy[i];
    if (iy < 1) iy = c + c;
    if (ix > 0 && ix <= r)
      if (bh[ix][iy]) S1.insert(find(bh[ix][iy]));
    iy = y + dy[i] + c;
    if (iy > c + c) iy = 1;
    if (ix > 0 && ix <= r)
      if (bh[ix][iy]) S2.insert(find(bh[ix][iy]));
  }
  for (set<int>::iterator it = S1.begin(); it != S1.end(); it++)
    if (S2.find(*it) != S2.end()) return;
  ans++;
  bh[x][y] = ++k;
  dsu[k] = k;
  bh[x][y + c] = ++k;
  dsu[k] = k;
  for (i = 0; i < 8; i++) {
    ix = x + dx[i];
    iy = y + dy[i];
    int a, b;
    if (ix > 0 && ix < r) {
      if (iy < 1)
        a = bh[ix][c + c];
      else
        a = bh[ix][iy];
      if (iy > c)
        b = bh[ix][0];
      else
        b = bh[ix][iy + c];
      if (a && find(k - 1) != find(a)) dsu[find(k - 1)] = a;
      if (b && find(k) != find(b)) dsu[find(k)] = b;
    }
  }
}
int main() {
  init();
  while (n--) {
    int x, y;
    scanf("%d %d", &x, &y);
    reclamation(x, y);
  }
  printf("%d\n", ans);
  return 0;
}
