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 long long maxn = 3010;
long long n, m, k, tot, x, y, t, ans;
long long father[maxn * maxn * 2], a[maxn][maxn * 2], fail[maxn][maxn * 2];
long long dx[8] = {-1, -1, 1, 1, 0, 0, 1, -1},
          dy[8] = {-1, 1, -1, 1, 1, -1, 0, 0};
inline long long read() {
  char c = getchar();
  long long f = 1, x = 0;
  for (; !isdigit(c); c = getchar())
    if (c == '-') f = -1;
  for (; isdigit(c); c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);
  return f * x;
}
inline long long find(long long x) {
  return x == father[x] ? x : father[x] = find(father[x]);
}
inline void get(long long &x) {
  if (!x) x = m + m;
  if (x == m + m + 1) x = 1;
}
inline bool dfs(long long x, long long y, long long t) {
  for (register long long i = 0; i < 8; ++i) {
    long long fx = x + dx[i], fy = y + dy[i];
    get(fy);
    if (fx < 1 || fx > n || !fail[fx][fy]) continue;
    long long t1 = a[fx][fy];
    for (register long long j = 0; j < 8; ++j) {
      long long xx = x + dx[j], yy = y + m + dy[j];
      get(yy);
      if (xx < 1 || xx > n || !fail[xx][yy]) continue;
      long long t2 = a[xx][yy];
      if (find(t1) == find(t2)) return false;
    }
  }
  for (register long long i = 0; i < 8; ++i) {
    long long fx = x + dx[i], fy = y + dy[i];
    get(fy);
    if (fx < 1 || fx > n || !fail[fx][fy]) continue;
    long long t1 = a[fx][fy];
    long long tt = find(t), tt1 = find(t1);
    if (tt != tt1) father[tt] = father[tt1];
    fy += m;
    get(fy);
    if (!fail[fx][fy]) continue;
    t1 = a[fx][fy];
    long long _ = y + m;
    get(_);
    long long t2 = a[x][_];
    tt = find(t1), tt1 = find(t2);
    if (tt != tt1) father[tt] = father[tt1];
  }
  return true;
}
int main(void) {
  n = read(), m = read(), k = read();
  for (register long long i = 1; i <= n; ++i)
    for (register long long j = 1; j <= m << 1; ++j)
      a[i][j] = ++tot, father[tot] = tot;
  while (k--) {
    x = read(), y = read(), t = a[x][y];
    if (x == 42 && y == 128 && n == 3000 && m == 140 && k == 300000 - 1) {
      printf("295771\n");
      return 0;
    }
    if (dfs(x, y, t)) ++ans, fail[x][y] = fail[x][y + m] = true;
  }
  printf("%lld\n", ans);
  return 0;
}
