#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define MAXN 300005
#define FOR(i, a, b) for(ll i = a; i <= b; i++)
ll n, t[2], pfx[MAXN], r = 0;
vector<array<ll, 2>> v(MAXN);
int main(){
cin >> n >> t[0] >> t[1];
FOR(i, 1, n) cin >> v[i][0] >> v[i][1];
sort(begin(v) + 1, begin(v) + 1 + n, [&](const auto &a, const auto &b) {
return a[0] - a[1] > b[0] - b[1];
});
priority_queue<ll> pq;
pfx[0] = 0;
FOR(i, 1, n){
pfx[i] = pfx[i - 1];
pfx[i] += v[i][0], pq.push(-v[i][0]);
while((ll)pq.size() > t[0]) pfx[i] += pq.top(), pq.pop();
}
priority_queue<ll>().swap(pq);
ll sfx = 0;
for(ll i = n + 1; i >= 1; i--){
if(i <= n){
sfx += v[i][1];
pq.push(-v[i][1]);
while((ll)pq.size() > t[1]) sfx += pq.top(), pq.pop();
}
if((ll)pq.size() == t[1] && i - 1 >= t[1]) r = max(r, sfx + pfx[i - 1]);
}
cout << r << endl;
}
