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 n, m, q, F[20000010], S[200010][2], t = 0, ans = 0, x, y;
bool B[20000010];
int getf(int x) { return F[x] == x ? x : getf(F[x]); }
void merge(int x, int y) {
  if (rand() & 1) swap(x, y);
  if (getf(x) != getf(y))
    S[++t][0] = getf(x), S[t][1] = F[getf(x)], F[getf(x)] = getf(y);
}
void rev() {
  for (; t; t--) F[S[t][0]] = S[t][1];
}
int main() {
  scanf("%d%d%d", &n, &m, &q);
  for (int i = 1; i <= n; i++)
    for (int j = 0; j <= m * 2 + 1; j++) B[((m * 2 + 5) * (i) + (j))] = 1;
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= m * 2; j++)
      F[((m * 2 + 5) * (i) + (j))] = ((m * 2 + 5) * (i) + (j)),
                             B[((m * 2 + 5) * (i) + (j))] = 0, t = 0;
  for (int i = 1; i <= n; i++)
    F[((m * 2 + 5) * (i) + (0))] = ((m * 2 + 5) * (1) + (0)),
                           F[((m * 2 + 5) * (i) + (m * 2 + 1))] =
                               ((m * 2 + 5) * (1) + (m * 2 + 1)),
                           t = 0;
  while (q--) {
    scanf("%d%d", &x, &y), t = 0;
  }
  return printf("%d\n", ans), 0;
}
