// #define DEBUG
#include <algorithm>
#include <iostream>
#include <vector>
#include <set>
using namespace std;
typedef long long llong;
int main()
{
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int n, aNum, bNum;
cin >> n >> aNum >> bNum;
struct City
{
int a, b;
};
vector<City> cities(n);
for (int i = 0; i < n; ++i)
cin >> cities[i].a >> cities[i].b;
if (!aNum)
{
sort(cities.begin(), cities.end(), [](const City& lhs, const City& rhs) {
return lhs.b > rhs.b;
});
long long ans = 0;
for (int i = 0; i < bNum; ++i)
ans += cities[i].b;
cout << ans;
exit(0);
}
if (!bNum)
{
sort(cities.begin(), cities.end(), [](const City& lhs, const City& rhs) {
return lhs.a > rhs.a;
});
long long ans = 0;
for (int i = 0; i < aNum; ++i)
ans += cities[i].a;
cout << ans;
exit(0);
}
sort(cities.begin(), cities.end(), [](const City& lhs, const City& rhs) {
return lhs.a - lhs.b > rhs.a - rhs.b;
});
vector<long long> pref(n, -30'000'000'000LL), suff(n, -30'000'000'000LL);
multiset<int> a;
long long sum = 0;
for (int i = 0; i < aNum; ++i)
{
a.insert(cities[i].a);
sum += cities[i].a;
}
pref[aNum - 1] = sum;
for (int i = aNum; i < n; ++i)
{
sum += cities[i].a;
a.insert(cities[i].a);
sum -= *a.begin();
a.erase(a.begin());
pref[i] = sum;
}
sum = 0;
multiset<int> b;
for (int i = 1; i <= bNum; ++i)
{
b.insert(cities[n - i].b);
sum += cities[n - i].b;
}
suff[n - bNum] = sum;
for (int i = bNum + 1; i <= n; ++i)
{
sum += cities[n - i].b;
b.insert(cities[n - i].b);
sum -= *b.begin();
b.erase(b.begin());
suff[n - i] = sum;
}
long long ans = 0;
for (int i = 0; i + 1 < n; ++i)
ans = max(ans, pref[i] + suff[i + 1]);
cout << ans;
}
