#include <iostream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <cstring>
#include <chrono>
#include <vector>
#include <map>
#include <random>
#include <set>
#include <algorithm>
#include <math.h>
#include <cstdio>
#include <stdio.h>
#include <queue>
#include <bitset>
#include <cstdlib>
#include <deque>
#include <cassert>
#include <stack>
using namespace std;
#define mp make_pair
#define f first
#define se second
#define pb push_back
#define ppb pop_back
#define emb emplace_back
#define ll long long
#define ull unsigned long long
#define cntbit(x) __builtin_popcount(x)
#define endl '\n'
#define uset unordered_set
#define umap unordered_map
#define pii pair<int, int>
#define ld long double
#define pll pair<long long, long long>
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T> inline T range(T l, T r) {
return uniform_int_distribution<T>(l, r)(rng);
}
inline void setin(string s) {
freopen(s.c_str(), "r", stdin);
}
inline void setout(string s) {
freopen(s.c_str(), "w", stdout);
}
template <typename T> void Min(T &a, T b) {
a = min(a, b);
}
template <typename T> void Max(T &a, T b) {
a = max(a, b);
}
#define int long long
const int mod = 998244353;
const int inf = 0x3f3f3f3f;
const int N = 3e5 + 15;
int n, x, y;
pii a[N];
int ans;
multiset <int> s;
int sum;
int pref[N], suff[N];
inline void solve() {
sort(a + 1, a + 1 + n, [&](pii a, pii b) {
return mp(a.f - a.se, a.f) > mp(b.f - b.se, b.f);
});
for(int i = 1; i <= x; ++i)
sum += a[i].f, s.insert(a[i].f);
pref[x] = sum;
for(int i = x + 1; i <= n; ++i) {
sum += a[i].f;
s.insert(a[i].f);
sum -= *s.begin();
s.erase(s.begin());
pref[i] = sum;
}
s.clear(), sum = 0;
for(int i = n - y + 1; i <= n; ++i)
sum += a[i].se, s.insert(a[i].se);
suff[n - y + 1] = sum;
for(int i = n - y; i; --i) {
sum += a[i].se;
s.insert(a[i].se);
sum -= *s.begin();
s.erase(s.begin());
suff[i] = sum;
}
for(int i = x; i <= n - y; ++i)
Max(ans, pref[i] + suff[i + 1]);
}
main() {
ios_base::sync_with_stdio(0); cout.tie(0); cin.tie(0);
// setin("input.txt");
cin >> n >> x >> y;
for(int i = 1; i <= n; ++i)
cin >> a[i].f >> a[i].se;
solve();
cout << ans << endl;
return 0;
}
