#include "bits/stdc++.h" using namespace std; #define ll long long #define vi vector #define vvi vector #define pi pair #define mp make_pair #define pb push_back #define MOD 1e9 + 7 #define PAI 3.1415 #define all(x) (x).begin(),(x).end() #define chmax(x,y) x = max(x,y) #define chmin(x,y) x = min(x,y) #define pr(x) cout << x << endl #define Endl endl #define rep(i,n) for(int i = 0 ; i < n; i++) const int dx[4] = {1,0,-1,0}; const int dy[4] = {0,1,0,-1}; const int ddx[8] = {-1,0,1,-1,1,-1,0,1}; const int ddy[8] = {-1,-1,-1,0,0,1,1,1}; const int inf = 99999999; const ll linf = 1LL << 62; ll gcd(ll a,ll b){ if(a < b)swap(a , b); if(a % b == 0) return b; else gcd(b, a%b); } ll lcm(ll a,ll b){ if(a < b)swap(a , b); return (a/gcd(a , b)) * b; } int main(){ ll w, h, n; cin >> w >> h >> n; vector vll(w + 10); set col, num; for(int i = 0; i < n; i++) { ll s, k; cin >> s >> k; vll[s]++; col.insert(s); num.insert(k); } ll ans = 0; for(ll i = 1; i <= w; i++) { if(vll[i] != 0) ans += h - vll[i]; } ans += (w - col.size()) * num.size(); pr(ans); return 0; }