#include<algorithm>
#include<iostream>
#include<vector>
#include<cstdio>
#include<set>
using namespace std;
#define int long long
struct SegmentTree{
int n;
vector<bool> lazy;
SegmentTree(){
n = 1 << 19;
lazy.assign(2 * n, false);
}
void push(int id, int l, int r) {
if (lazy[id]) {
if (l != r) {
lazy[2 * id] = true;
lazy[2 * id + 1] = true;
}
lazy[id] = false;
}
}
void set_renew(int u, int v, int id, int l, int r) {
if (l > v || r < u) return;
if (l >= u && r <= v) {
lazy[id] = true;
return;
}
push(id, l, r);
int mid = (l + r) / 2;
set_renew(u, v, 2 * id, l, mid);
set_renew(u, v, 2 * id + 1, mid + 1, r);
}
void set_renew(int l, int r) { set_renew(l, r - 1, 1, 0, n - 1); }
bool is_renew(int p, int id, int l, int r) {
if (l == r){
int res = lazy[id];
lazy[id] = 0;
return res;
}
push(id, l, r);
int mid = (l + r) / 2;
if (p <= mid) return is_renew(p, 2 * id, l, mid);
else return is_renew(p, 2 * id + 1, mid + 1, r);
}
bool is_renew(int p) { return is_renew(p, 1, 0, n - 1); }
} st;
struct action{
int pos, act, left, right;
};
const int maxn = 1e5 + 5;
int x1[maxn], y1[maxn], x2[maxn], y2[maxn];
int target[2 * maxn], bit[3 * maxn];
vector<int> lab;
void update(int p, int v){
for(; p < 3 * maxn; p += p & -p) bit[p] += v;
}
int get(int p){
int res = 0;
for(; p; p -= p & -p) res += bit[p];
return res;
}
int find(int u){
return (lab[u] < 0) ? u : (lab[u] = find(lab[u]));
}
bool join(int u, int v){
u = find(u), v = find(v);
if(u == v) return false;
if(lab[u] > lab[v]) swap(u, v);
lab[u] += lab[v];
lab[v] = u;
return true;
}
void adjust(int p){
if(st.is_renew(p)){
lab.push_back(-1);
target[p] = lab.size() - 1;
}
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int w, h, n; cin >> w >> h >> n;
for(int i = 0; i < n; i++){
cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
if(x1[i] > x2[i]) swap(x1[i], x2[i]);
if(y1[i] > y2[i]) swap(y1[i], y2[i]);
}
for(int i = 0; i < 2 * n; i++) target[i] = -1;
x1[n] = 0;
y1[n] = 0;
x2[n] = w;
y2[n] = 0;
x1[n + 1] = 0;
y1[n + 1] = 0;
x2[n + 1] = 0;
y2[n + 1] = h;
x1[n + 2] = w;
y1[n + 2] = 0;
x2[n + 2] = w;
y2[n + 2] = h;
x1[n + 3] = 0;
y1[n + 3] = h;
x2[n + 3] = w;
y2[n + 3] = h;
n += 4;
vector<int> compress;
for(int i = 0; i < n; i++){
compress.push_back(x1[i]);
compress.push_back(x2[i]);
}
compress.push_back(-1);
sort(compress.begin(), compress.end());
compress.erase(unique(compress.begin(), compress.end()), compress.end());
for(int i = 0; i < n; i++){
x1[i] = lower_bound(compress.begin(), compress.end(), x1[i]) - compress.begin();
x2[i] = lower_bound(compress.begin(), compress.end(), x2[i]) - compress.begin();
}
vector<action> a;
for(int i = 0; i < n; i++){
if(x1[i] == x2[i]){
a.push_back({y1[i], 0, x1[i], -1});
a.push_back({y2[i], 2, x1[i], -1});
}else a.push_back({y1[i], 1, x1[i], x2[i]});
}
sort(a.begin(), a.end(), [&](action x, action y){
return x.pos < y.pos || (x.pos == y.pos && x.act < y.act);
});
set<int> s;
s.insert(0);
target[0] = 0;
lab.push_back(-1);
int res = 0;
for(auto [pos, act, left, right]: a){
if(act == 0){
int lf = *--s.lower_bound(left);
adjust(lf);
adjust(left);
target[left] = target[lf];
update(left, 1);
s.insert(left);
}else if(act == 1){
int count = get(right) - get(left - 1);
if(count < 2) continue;
res += count - 1;
st.set_renew(left, *--s.upper_bound(right));
}else{
int lf = *--s.lower_bound(left);
adjust(lf);
adjust(left);
if(join(target[lf], target[left])) res--;
update(left, -1);
s.erase(left);
}
}
cout << res;
}
