#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define len(s) (ll) s.size()
const ll I = 5e5 + 9;
using namespace std;
ll n, m, o;
pair<ll, ll> b[I], a[I], S[I * 4];
bool check[I];
void build(int x, int l, int r)
{
if (l == r)
{
S[x].fi = a[l].se; // min money
S[x].se = l; // pos
return;
}
int mid = (l + r) / 2;
build(x * 2, l, mid);
build(x * 2 + 1, mid + 1, r);
int id;
if (S[x * 2].fi < S[x * 2 + 1].fi)
id = x * 2;
else
id = x * 2 + 1;
S[x].fi = S[id].fi;
S[x].se = S[id].se;
}
void update(int x, int l, int r, int pos)
{
if (pos < l || pos > r || r < l)
return;
if (pos == l && pos == r)
{
S[x].fi = 1000000000000000;
return;
}
int mid = (l + r) / 2;
update(x * 2, l, mid, pos);
update(x * 2 + 1, mid + 1, r, pos);
int id;
if (S[x * 2].fi < S[x * 2 + 1].fi)
id = x * 2;
else
id = x * 2 + 1;
S[x].fi = S[id].fi;
S[x].se = S[id].se;
}
int get(int x, int l, int r, int L, int R)
{
if (R < l || r < L || R < L || r < l)
return -1;
if (L <= l && r <= R)
return S[x].se;
int mid = (l + r) / 2;
ll p = get(x * 2, l, mid, L, R);
if (p == -1)
p = get(x * 2 + 1, mid + 1, r, L, R);
else
{
int np = get(x * 2 + 1, mid + 1, r, L, R);
if (np != -1)
if (a[p].se > a[np].se)
p = np;
}
return p;
}
int main()
{
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m >> o;
for (int i = 1; i <= n; i++)
cin >> a[i].se >> a[i].fi; // money, lim
sort(a + 1, a + n + 1);
build(1, 1, n);
for (int i = 1; i <= m; i++)
cin >> b[i].fi >> b[i].se;
sort(b + 1, b + m + 1, greater<pair<ll, ll>>());
ll mxprof = 0;
for (int i = 1, dem = 0; i <= m && dem < o; i++)
{
for (int j = 1; j <= n; j++)
{
if (check[j])
continue;
if (a[j].fi >= b[i].se && a[j].se <= b[i].fi)
{
dem++;
mxprof += b[i].fi - a[j].se;
check[j] = true;
break;
}
}
}
cout << mxprof;
return 0;
}
