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 gint() {
  char c;
  int f = 1;
  while (c = getchar(), c < 48 || c > 57)
    if (c == '-') f = -1;
  int x = 0;
  for (; c > 47 && c < 58; c = getchar()) {
    x = x * 10 + c - 48;
  }
  return x * f;
}
stack<pair<int, int> > st;
bool map[3001][6001];
int f[3000 * 6100];
int r, c, n, ans;
int find(int x) {
  if (x == f[x]) return x;
  st.push(pair<int, int>(x, f[x]));
  return f[x] = find(f[x]);
}
const int dx[] = {0, 0, 1, -1, 1, -1, 1, -1};
const int dy[] = {1, -1, 0, 0, 1, -1, -1, 1};
inline bool check(int x, int y) {
  map[x][y] = map[x][y + c] = 1;
  int F = find(x * 6001 + y);
  for (int i = 0, x1, y1; i < 8; ++i) {
    x1 = x + dx[i], y1 = y + dy[i];
    if (!x || x > r) continue;
    if (!y1) y1 = 2 * c;
    if (!map[x1][y1]) continue;
    int f1 = find(x1 * 6001 + y1);
    if (F == f1) continue;
    st.push(pair<int, int>(f1, f1));
    f[f1] = F;
  }
  F = find(x * 6001 + y + c);
  for (int i = 0, x1, y1; i < 8; ++i) {
    x1 = x + dx[i], y1 = y + c + dy[i];
    if (!x || x > r) continue;
    if (y1 == 2 * c + 1) y1 = 1;
    if (!map[x1][y1]) continue;
    int f1 = find(x1 * 6001 + y1);
    if (F == f1) continue;
    st.push(pair<int, int>(f1, f1));
    f[f1] = F;
  }
  if (find(x * 6001 + y + c) != find(x * 6001 + y)) {
    while (!st.empty()) st.pop();
    return 1;
  }
  while (!st.empty()) f[st.top().first] = st.top().second, st.pop();
  map[x][y] = map[x][y + c] = 0;
  return 0;
}
int main() {
  r = gint(), c = gint();
  for (int i = 1; i <= r; ++i)
    for (int j = 1; j <= 2 * c; ++j) f[i * 6001 + j] = i * 6001 + j;
  n = gint();
  for (int i = 1, x, y; i <= n; ++i) {
    x = gint(), y = gint();
    ans += check(x, y);
  }
  return printf("%d\n", ans), 0;
}
