#include <bits/stdc++.h>
using namespace std;
const int maxn = 300005;
int n, music, sport;
pair<int, int> a[maxn];
multiset<pair<int, pair<int, int>>, greater<pair<int, pair<int, int>>>> currentMusic;
multiset<pair<int, int>, greater<pair<int, int>>> otherByMusic;
multiset<pair<int, int>, greater<pair<int, int>>> otherBySport;
void fastIO()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
}
int main()
{
fastIO();
cin >> n >> music >> sport;
for (int i = 1; i <= n; ++i)
{
cin >> a[i].first >> a[i].second;
}
sort(a + 1, a + n + 1, greater<pair<int, int>>());
long long ans = 0;
for (int i = 1; i <= music; ++i)
{
ans += a[i].first;
currentMusic.insert({a[i].second - a[i].first, {a[i].first, a[i].second}});
}
for (int i = music + 1; i <= n; ++i)
{
otherByMusic.insert({a[i].first, a[i].second});
otherBySport.insert({a[i].second, a[i].first});
}
for (int steps = 1; steps <= sport; ++steps)
{
long long case1 = 0, case2 = 0;
//long long case1 = (*otherBySport.begin());
//long long case2 = (*currentMusic.begin()) + (*otherByMusic.begin());
pair<int, int> currSport = (*otherBySport.begin());
case1 = currSport.first;
pair<int, pair<int, int>> currMus = (*currentMusic.begin());
pair<int, int> otherMus = (*otherByMusic.begin());
case2 = currMus.first + otherMus.first;
if (case1 >= case2)
{
ans += case1;
auto it = otherBySport.begin();
int x = it -> first;
int y = it -> second;
otherBySport.erase(otherBySport.find({x, y}));
otherByMusic.erase(otherByMusic.find({y, x}));
}
else
{
ans += case2;
auto it = currentMusic.begin();
pair<int, pair<int, int>> curr = *it;
currentMusic.erase(currentMusic.find(curr));
pair<int, int> currMusic = (*otherByMusic.begin());
otherByMusic.erase(otherByMusic.find(currMusic));
otherBySport.erase(otherBySport.find({currMusic.second, currMusic.first}));
currentMusic.insert({currMusic.second - currMusic.first, currMusic});
}
}
cout << ans << endl;
return 0;
}
