#include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define REP(i, n) for(ll i = 0;i < n;i++) #define REPR(i, n) for(ll i = n;i >= 0;i--) #define FOR(i, m, n) for(ll i = m;i < n;i++) #define FORR(i, m, n) for(ll i = m;i >= n;i--) #define REPO(i, n) for(ll i = 1;i <= n;i++) #define ll long long #define INF (ll)1 << 60 #define MINF (-1 * INF) #define ALL(n) n.begin(),n.end() #define MOD 1000000007 #define P pair ll a, b, n, s1[110], s2[110]; map m; int main() { cin >> a >> b >> n; REP(i, n)cin >> s1[i] >> s2[i]; REP(i, n) { REPO(j, a)m[P(j, s2[i])]++; REPO(j, b)m[P(s1[i], j)]; } cout << m.size() - n << endl; }