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 R, C, Q, cc, f[20000005];
void setIO(string a) {}
int find(int x) {
  if (f[x] == x) return x;
  return f[x] = find(f[x]);
}
int uid(int x, int y) { return x * (2 * C) + y; }
void Union(int x, int y) {
  x = find(x);
  y = find(y);
  f[x] = y;
}
int sa[15], sb[15], ans, land[3005][6005];
int main() {
  scanf("%d%d%d", &R, &C, &Q);
  cc = C << 1;
  for (int i = (1); i <= (2 * R * C); i++) f[i] = i;
  while (Q--) {
    int x, y;
    *sa = *sb = 0;
    scanf("%d%d", &x, &y);
    --x;
    --y;
    for (int dx = (-1); dx <= (1); dx++)
      for (int dy = (-1); dy <= (1); dy++) {
        int xx = x + dx, yy = (y + dy + cc) % cc;
        if (xx < 0 || xx >= R) continue;
        if (!land[xx][yy]) continue;
        sa[++*sa] = uid(xx, yy);
        sb[++*sb] = uid(xx, (yy + C) % cc);
      }
    int fail = 0;
    for (int i = (1); i <= (*sa); i++)
      for (int j = (1); j <= (*sb); j++) {
        if (find(sa[i]) == find(sb[j])) {
          fail = 1;
          break;
        }
      }
    if (fail) continue;
    ans++;
    land[x][y] = 1;
    land[x][(y + C) % cc] = 1;
    int Now = uid(x, y), Noww = uid(x, (y + C) % cc);
    for (int i = (1); i <= (*sa); i++) Union(Now, sa[i]);
    for (int i = (1); i <= (*sb); i++) Union(Noww, sb[i]);
  }
  printf("%d\n", ans);
  return 0;
}
