#include<bits/stdc++.h>
using namespace std;
#define sz(v) (int)(v).size()
#define all(v) (v).begin(), (v).end()
#define compact(v) (v).erase(unique(all(v)), (v).end())
#define dbg(x) "[" #x " = " << (x) << "]"
using ll = long long;
struct Query{
int p, op, l, r;
Query() {}
Query(int p, int op, int l, int r): p(p), op(op), l(l), r(r) {}
inline bool operator < (const Query& q) const{
return make_tuple(p, op, l) < make_tuple(q.p, q.op, q.l);
}
};
const int N = 1e5 + 10;
int n, W, H, cut[N][4], id[N << 1]; ll ans;
vector<Query> Q; vector<int> comp; set<int> line;
namespace tr{
int st[N << 3];
void down(int id){
if(st[id]){
st[id << 1] |= st[id];
st[id << 1|1] |= st[id];
st[id] = 0;
}
}
inline void update(int id, int l, int r, int u, int v){
if(l >= u && r <= v){
st[id] = 1;
}
else{
int m = l+r>>1; down(id);
if(u <= m) update(id << 1, l, m, u, v);
if(v > m) update(id << 1|1, m+1, r, u, v);
}
}
void updPoint(int x, int val){
int id = 1, l = 0, r = W;
for(; l < r ;){
int m = l+r>>1; down(id);
if(x <= m)
id = id << 1, r = m;
else id = id << 1|1, l = m+1;
}
st[id] = val;
}
int query(int x){
int id = 1, l = 0, r = W;
for(; l < r ;){
int m = l+r>>1; down(id);
if(x <= m)
id = id << 1, r = m;
else id = id << 1|1, l = m+1;
}
assert(l == x);
return st[id];
}
void update(int l, int r){
update(1, 0, W, l, r);
}
}
namespace bit{
int bit[N << 1];
void update(int p, int val){
for(; p <= W; p += p & -p){
bit[p] += val;
}
}
int get(int p){
int ans = 0;
for(; p > 0; p -= p & -p){
ans += bit[p];
}
return ans;
}
int query(int l, int r){
return get(min(W, r)) - get(l - 1);
}
}
namespace dsu{
vector<int> par;
int asc(int x){
return par[x] < 0 ? x : par[x] = asc(par[x]);
}
void join(int u, int v){
u = asc(u), v = asc(v);
if(u != v){
--ans;
if(par[u] > par[v]) swap(u, v);
par[u] += par[v], par[v] = u;
}
}
void upd(int p){
if(tr::query(p)){
id[p] = sz(par);
par.push_back(-1);
tr::updPoint(p, 0);
}
}
}
void Main()
{
cin >> W >> H >> n;
for(int i = 1; i <= n; i++){
for(int j = 0; j < 4; j++){
cin >> cut[i][j];
}
if(cut[i][0] > cut[i][2]) swap(cut[i][0], cut[i][2]);
if(cut[i][1] > cut[i][3]) swap(cut[i][1], cut[i][3]);
}
auto def = [&](int p, int x1, int y1, int x2, int y2) -> void{
cut[p][0] = x1, cut[p][1] = y1, cut[p][2] = x2, cut[p][3] = y2;
};
def(n + 1, 0, 0, W, 0);
def(n + 2, 0, 0, 0, H);
def(n + 3, W, 0, W, H);
def(n + 4, 0, H, W, H);
n += 4;
for(int i = 1; i <= n; i++){
comp.push_back(cut[i][0]);
comp.push_back(cut[i][2]);
}
sort(all(comp)), compact(comp); W = sz(comp);
for(int i = 1; i <= n; i++){
cut[i][0] = lower_bound(all(comp), cut[i][0]) - comp.begin() + 1;
cut[i][2] = lower_bound(all(comp), cut[i][2]) - comp.begin() + 1;
assert(cut[i][0] <= cut[i][2]);
if(cut[i][0] == cut[i][2]){
// create a line and end a line at [cut[i][1], cut[i][3]]
Q.emplace_back(cut[i][1] , +1, cut[i][0], -1);
Q.emplace_back(cut[i][3]+1, -1, cut[i][0], -1);
}
else{
// create a horizontal line (renew element in range [cut[i][0], cut[i][2]])
Q.emplace_back(cut[i][1] , +2, cut[i][0], cut[i][2]);
}
}
sort(all(Q));
tr::updPoint(0, 1); line.insert(0); dsu::upd(0);
for(Query& cur_q : Q){
if(cur_q.op == +1){
int l = cur_q.l, pl = *(--line.lower_bound(l));
dsu::upd(pl), dsu::upd(l);
id[l] = id[pl];
line.insert(l);
bit::update(l, +1);
}
else if(cur_q.op == +2){
int l = cur_q.l, r = cur_q.r;
ans = ans + 1ll * (max(0, bit::query(l, r) - 1));
tr::update(*line.lower_bound(l), *--line.upper_bound(r) - 1);
}
else if(cur_q.op == -1){
int l = cur_q.l, pl = *(--line.lower_bound(l));
dsu::upd(pl), dsu::upd(l);
dsu::join(id[pl], id[l]);
line.erase(l);
bit::update(l, -1);
}
}
cout << ans << "\n";
}
int32_t main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
#define name "InvMOD"
if(fopen(name".INP", "r")){
freopen(name".INP", "r", stdin);
freopen(name".OUT", "w", stdout);
}
int t = 1; while(t--) Main();
return 0;
}
