/*************************************
* author: marvinthang *
* created: 07.06.2023 11:12:43 *
*************************************/
#include "robots.h"
#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define left ___left
#define right ___right
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
#define MASK(i) (1LL << (i))
#define BIT(x, i) ((x) >> (i) & 1)
#define __builtin_popcount __builtin_popcountll
#define ALL(v) (v).begin(), (v).end()
#define REP(i, n) for (int i = 0, _n = (n); i < _n; ++i)
#define REPD(i, n) for (int i = (n); i--; )
#define FOR(i, a, b) for (int i = (a), _b = (b); i < _b; ++i)
#define FORD(i, b, a) for (int i = (b), _a = (a); --i >= _a; )
#define FORE(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORDE(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)
#define scan_op(...) istream & operator >> (istream &in, __VA_ARGS__ &u)
#define print_op(...) ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
#include "debug.h"
#else
#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#define DB(...) 23
#define db(...) 23
#define debug(...) 23
#endif
template <class U, class V> scan_op(pair <U, V>) { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>) { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>) { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")"; else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }
// end of template
int putaway(int A, int B, int T, int X[], int Y[], int W[], int S[]) {
sort(X, X + A);
sort(Y, Y + B, greater<int>());
vector <pair <int, int>> Z;
REP(i, T) Z.emplace_back(W[i], S[i]);
sort(ALL(Z));
auto check = [&] (int t) {
int j = 0;
priority_queue <int> pq;
REP(i, A) {
while (j < T && Z[j].fi < X[i]) pq.push(Z[j++].se);
REP(love, t) {
if (pq.empty()) break;
pq.pop();
}
}
while (j < T) pq.push(Z[j++].se);
REP(i, B) {
REP(love, t) {
if (pq.empty()) break;
if (pq.top() >= Y[i]) return false;
pq.pop();
}
}
return pq.empty();
};
int l = 1, r = T;
while (l <= r) {
int m = l + r >> 1;
if (check(m)) r = m - 1;
else l = m + 1;
}
return l > T ? -1 : l;
}
#ifdef LOCAL
#include <stdio.h>
#include <stdlib.h>
#include "robots.h"
#define fail(s, x...) do { \
fprintf(stderr, s "\n", ## x); \
exit(1); \
} while(0)
#define MAX_A 50000
#define MAX_B 50000
#define MAX_T 500000
static int X[MAX_A];
static int Y[MAX_B];
static int W[MAX_T];
static int S[MAX_T];
int main() {
int A, B, T, i;
int res;
FILE *f = fopen("robots.in", "r");
if (!f)
fail("Failed to open input file.");
res = fscanf(f, "%d", &A);
if (res != 1)
fail("Failed to read A from input file.");
if (A < 0 || A > MAX_A)
fail("A is out of bounds.");
res = fscanf(f, "%d", &B);
if (res != 1)
fail("Failed to read B from input file.");
if (B < 0 || B > MAX_B)
fail("B is out of bounds.");
res = fscanf(f, "%d", &T);
if (res != 1)
fail("Failed to read T from input file.");
if (T < 1 || T > MAX_T)
fail("T is out of bounds.");
for (i = 0; i < A; i++) {
res = fscanf(f, "%d", &X[i]);
if (res != 1)
fail("Failed to read data from input file.");
}
for (i = 0; i < B; i++) {
res = fscanf(f, "%d", &Y[i]);
if (res != 1)
fail("Failed to read data from input file.");
}
for (i = 0; i < T; i++) {
res = fscanf(f, "%d%d", &W[i], &S[i]);
if (res != 2)
fail("Failed to read data from input file.");
}
fclose(f);
int answer = putaway(A, B, T, X, Y, W, S);
printf("%d\n", answer);
return 0;
}
#endif
