#include <bits/stdc++.h>
#define ll long long
using namespace std;
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
// freopen("TAMCAM.inp", "r", stdin);
// freopen("TAMCAM.out", "w", stdout);
int k, n, m;
cin >> k >> n >> m;
vector<pair<int, int>> a(k);
for(pair<int, int> &o: a){
cin >> o.first >> o.second;
}
sort(a.begin(), a.end(), [&](pair<int, int> a, pair<int, int> b){
return a.second - a.first < b.second - b.first;
});
vector<ll> L(k + 3, 0), R(k + 3, 0);
{
priority_queue<ll, vector<ll>, greater<ll>> pq;
ll cur = 0;
for(int i=1; i<=k; i++){
cur += 1LL * a[i - 1].first;
pq.push(a[i - 1].first);
if((int)pq.size() > n){
cur -= pq.top();
pq.pop();
}
L[i] = cur;
}
}
{
priority_queue<ll, vector<ll>, greater<ll>> pq;
ll cur = 0;
for(int i=k; i>=1; i--){
cur += 1LL * a[i - 1].second;
pq.push(a[i - 1].second);
if((int)pq.size() > m){
cur -= pq.top();
pq.pop();
}
R[i] = cur;
}
}
ll ans = 0;
for(int i=n; i<=k-m; i++){
ans = max(ans, L[i] + R[i + 1]);
}
cout << ans << '\n';
return 0;
}
