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 MAXN = 3003;
int n, m, q;

int idx[MAXN][MAXN * 2];
int z;

int fa[MAXN * MAXN * 2];

bool land[MAXN][MAXN * 2];
int nRem;
pair<int, int> rem[MAXN * MAXN * 2];

int find(int i) {
  if (i == fa[i]) return i;
  rem[nRem++] = make_pair(i, fa[i]);
  return fa[i] = find(fa[i]);
}

void reclamate(int x, int y) {
  for (int i = -1; i <= 1; i++)
    for (int j = -1; j <= 1; j++) {
      int p = x + i, q = y + j;
      if (p < 1 || q < 1 || p > n || q > m * 2) continue;
      if (! land[p][q]) continue;
      int a = find(idx[x][y]), b = find(idx[p][q]);
      rem[nRem++] = make_pair(a, fa[a]);
      fa[a] = b;
    }
}

int main () {
  scanf("%d%d%d", &n, &m, &q);
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= m << 1; j++) {
      fa[z] = z;
      idx[i][j] = z++;
    }
  
  int ans = 0;
  for (int i = 0; i < q; i++) {
    int x, y;
    scanf("%d%d", &x, &y);
    nRem = 0;
    land[x][y] = land[x][y + m] = true;
    reclamate(x, y);
    reclamate(x, y + m);
    if (find(idx[x][y]) == find(idx[x][y + m])) {
      while (nRem > 0) {
        int p = rem[--nRem].first;
        fa[p] = rem[nRem].second;
      }
      land[x][y] = land[x][y + m] = false;
    }
    else {
      ans++;
    }
  }
  printf("%d\n", ans);
  return 0;
}
