// ~ Be Name Khoda ~ //
#include <bits/stdc++.h>
//#pragma GCC optimize ("O3")
#pragma GCC target("avx2")
#pragma GCC optimize("unroll-loops,Ofast")
using namespace std;
typedef long long ll;
#define pb push_back
#define mp make_pair
#define all(x) x.begin(), x.end()
#define fi first
#define se second
const int maxn = 1e6 + 10;
const int maxn5 = 5e3 + 10;
const int maxnt = 1.2e6 + 10;
const int maxn3 = 1e3 + 10;
const int mod = 1e9 + 7;
const ll inf = 1e18;
int d, mx, lnk[maxn5], must[2][maxn5];
int keep[maxn5], sz[maxn5], ksz[maxn5], klnk[maxn5];
bool mark[maxn5];
vector <int> req[maxn5];
void join(int a, int b){
if(lnk[a] == b)
return;
int u = lnk[a], v = lnk[b];
lnk[u] = v;
lnk[v] = u;
sz[u] = sz[v] = sz[u] + sz[v];
mx = max(mx, sz[u]);
}
void inser(int id){
mark[id] = true;
lnk[id] = id;
sz[id] = 1;
mx = max(mx, 1);
int pre = (!id ? d - 1 : id - 1);
int nxt = (id == d - 1 ? 0 : id + 1);
if(mark[pre])
join(pre, id);
if(mark[nxt])
join(nxt, id);
}
void pass(int id){
for(auto x : req[id]){
must[0][x]--;
//cout << "saw " << id << ' ' << x << ' ' << must[0][x] << endl;
if(must[0][x] == 0)
inser(x);
}
}
int main()
{
ios_base::sync_with_stdio(false); cin.tie(0);
int n, m; cin >> n >> m >> d;
int tobe = 0;
for(int i = 0; i < n; i++){
int a, b; cin >> a >> b;
must[0][a]++;
must[1][b]++;
if(must[1][b] == 1)
tobe++;
}
for(int i = 0; i < m; i++){
int a, b; cin >> a >> b;
must[0][a]++;
req[b].pb(a);
}
for(int i = 0; i < d; i++)
keep[i] = must[0][i];
int ans = d * d;
for(int j = 0; j < d; j++){
lnk[j] = j;
mark[j] = false;
}
for(int j = 0; j < d; j++) if(must[0][j] == 0)
inser(j);
for(int j = 0; j < d; j++){
klnk[j] = lnk[j];
ksz[j] = sz[j];
}
int keepmx = mx;
for(int i = 0; i < d; i++){
//cout << "in " << i << endl;
mx = keepmx;
for(int j = 0; j < d; j++){
must[0][j] = keep[j];
mark[j] = (keep[j] == 0);
lnk[j] = klnk[j];
sz[j] = ksz[j];
}
int seen = (must[1][i] > 0);
int j = i, len = 1;
pass(i);
while(seen < tobe && len < ans){
j++;
len++;
if(j == d)
j = 0;
pass(j);
seen += (must[1][j] > 0);
}
if(len >= ans)
continue;
ans = min(ans, (d - mx) * len);
//cout << i << ' ' << j << ' ' << len << ' ' << mx << ' ' << ans << endl;
len++;
j++;
if(j == d)
j = 0;
for(; len <= min(ans, d); j = (j + 1 == d ? 0 : j + 1), len++){
pass(j);
ans = min(ans, (d - mx) * len);
//cout << j << ' ' << len << ' ' << mx << ' ' << ans << endl;
}
}
cout << ans << endl;
}
