#include<cstdio>
#include<algorithm>
#include<set>
#include<vector>
using namespace std;
const int MAXN = 100020;
struct seg_tree
{
static const int DEPTH = 19;
static const int SIZE = 1<<DEPTH;
int bit[1<<(DEPTH+1)];
int renew[1<<(DEPTH+1)];
seg_tree() { }
void init()
{
for(int i=0;i<2*SIZE;i++) bit[i] = renew[i] = 0;
}
void add(int p, int v)
{
p += SIZE;
while(p){
bit[p] += v;
p >>= 1;
}
}
int query(int l, int r)
{
l += SIZE;
r += SIZE;
int ret = 0;
while(l < r){
if(l&1) ret += bit[l++];
if(r&1) ret += bit[--r];
l >>= 1; r >>= 1;
}
return ret;
}
void set_renew(int l, int r)
{
l += SIZE;
r += SIZE;
while(l < r){
if(l&1) renew[l++] = 1;
if(r&1) renew[--r] = 1;
l >>= 1; r >>= 1;
}
}
bool is_renew(int p)
{
p += SIZE;
while(p){
if(renew[p]) return true;
p >>= 1;
}
return false;
}
void unset_renew(int p)
{
p += SIZE;
for(int i=DEPTH-1;i>0;i--){
if(renew[p >> i]){
renew[p >> i] = 0;
renew[(p>>i)*2] = renew[(p>>i)*2+1] = 1;
}
}
renew[p] = 0;
}
};
struct action
{
int pos, act, left, right;
action(int p, int a, int l, int r)
{
pos = p; act = a; left = l; right = r;
}
};
inline bool operator<(const action& a, const action& b)
{
return a.pos < b.pos || (a.pos == b.pos && a.act < b.act);
}
int W, H, N;
int x1[MAXN], y1[MAXN], x2[MAXN], y2[MAXN];
vector<int> uf;
seg_tree seg;
int target[MAXN*2];
int root(int p)
{
return (uf[p] < 0) ? p : (uf[p] = root(uf[p]));
}
bool join(int p, int q)
{
p = root(p);
q = root(q);
if(p==q) return false;
if(uf[p] < uf[q]) swap(p, q);
uf[p] = uf[q];
uf[q] = p;
return true;
}
void adjust(int p)
{
if(seg.is_renew(p)){
uf.push_back(-1);
seg.unset_renew(p);
target[p] = uf.size() - 1;
}
}
int main()
{
scanf("%d%d%d", &W, &H, &N);
for(int i=0;i<N;i++){
scanf("%d%d%d%d", 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> xs;
for(int i=0;i<N;i++){
xs.push_back(x1[i]);
xs.push_back(x2[i]);
}
xs.push_back(-1);
sort(xs.begin(), xs.end());
xs.erase(unique(xs.begin(), xs.end()), xs.end());
for(int i=0;i<N;i++){
x1[i] = lower_bound(xs.begin(), xs.end(), x1[i]) - xs.begin();
x2[i] = lower_bound(xs.begin(), xs.end(), x2[i]) - xs.begin();
}
set<int> S;
S.insert(0);
target[0] = 0;
uf.push_back(-1);
vector<action> A;
for(int i=0;i<N;i++){
if(x1[i] == x2[i]){
A.push_back(action(y1[i], 0, x1[i], -1));
A.push_back(action(y2[i], 2, x1[i], -1));
}else{
A.push_back(action(y1[i], 1, x1[i], x2[i]));
}
}
sort(A.begin(), A.end());
long long ret = 0;
for(int i=0;i<A.size();i++){
action V = A[i];
if(V.act == 0){
int lf = *--S.lower_bound(V.left);
adjust(lf); adjust(V.left);
target[V.left] = target[lf];
S.insert(V.left);
seg.add(V.left, 1);
}else if(V.act == 1){
int count = seg.query(V.left, V.right+1);
if(count < 2) continue;
ret += count - 1;
seg.set_renew(V.left, *--S.upper_bound(V.right));
}else if(V.act == 2){
int lf = *--S.lower_bound(V.left);
adjust(lf); adjust(V.left);
if(join(target[lf], target[V.left])) --ret;
S.erase(V.left);
seg.add(V.left, -1);
}
}
printf("%lld\n", ret);
return 0;
}
