typedef long long ll;

#define REP(i,n) for(int i=0; i<(int)(n); i++)

#include <queue>
#include <cstdio>
inline int getInt(){ int s; scanf("%d", &s); return s; }

#include <set>

using namespace std;

int main(){
  const int n = getInt();
  const int m = getInt();

  const int k = getInt();

  vector<int> a(n);
  vector<int> b(m);

  REP(i,k){
    a[getInt() - 1]++;
    b[getInt() - 1]++;
  }

  int t = 0;
  REP(i,m) t += !!b[i];

  ll ans = 0;
  REP(i,n){
    if(a[i]) ans += m - a[i];
    else ans += t;
  }

  printf("%lld\n", ans);

  return 0;
}