#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> ii;
#define fi first
#define se second
#define mask(i) (1LL << (i))
const int N = 3e5 + 5;
const ll inf = 1e17;
int k, n, m;
ii a[N];
ll pref[N], suf[N];
bool cmp(ii a, ii b) { return a.fi - a.se > b.fi - b.se; }
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin >> k >> n >> m;
for (int i = 1; i <= k; i++) cin >> a[i].fi >> a[i].se;
sort(a + 1, a + k + 1, cmp);
priority_queue<ll, vector<ll>, greater<ll>> q1;
ll sum = 0;
for (int i = 1; i <= k; i++) {
sum += a[i].fi; q1.push(a[i].fi);
while (q1.size() > n) {
sum -= q1.top(); q1.pop();
}
pref[i] = sum;
}
priority_queue<ll, vector<ll>, greater<ll>> q2;
sum = 0;
for (int i = k; i >= 1; i --) {
sum += a[i].se; q2.push(a[i].se);
while (q2.size() > m) {
sum -= q2.top(); q2.pop();
}
suf[i] = max(sum, suf[i + 1]);
}
ll res = 0;
for (int i = n; i <= k - m; i++) {
res = max(res, pref[i] + suf[i]);
}
cout << res;
}
