#include <bits/stdc++.h>
#define int long long
using namespace std;
const int nmax = 3e5 + 1;
struct str {
int a, b;
} v[nmax];
bool fa[nmax], fb[nmax];
int32_t main() {
int n, a, b;
cin >> n >> a >> b;
set<pair<int, int>> ra, rb;
for(int i = 1; i <= n; i++) {
cin >> v[i].a >> v[i].b;
v[i].a = -v[i].a, v[i].b = -v[i].b;
ra.insert({v[i].a, i});
rb.insert({v[i].b, i});
}
for(int i = 1; i <= a; i++) {
auto [val, poz] = *ra.begin();
fa[poz] = 1;
ra.erase({val, poz});
}
for(int i = 1; i <= b; i++) {
auto [val, poz] = *rb.begin();
fb[poz] = 1;
rb.erase({val, poz});
}
for(int i = 1; i <= n; i++) {
if(fa[i] || fb[i]) {
// mereu o sa fie marcat?
ra.erase({v[i].a, i});
rb.erase({v[i].b, i});
}
}
for(int i = 1; i <= n; i++) {
if(fa[i] == 1 && fb[i] == 1) {
int difa = v[i].a - (*ra.begin()).first;
int difb = v[i].b - (*rb.begin()).first;
// cout << "! " << difa << " " << difb << '\n';
if(difa > difb) {
fa[i] = 0;
auto [val, poz] = *ra.begin();
fa[poz] = 1;
ra.erase({val, poz});
rb.erase({v[poz].b, poz});
} else if(difa < difb) {
fb[i] = 0;
auto [val, poz] = *rb.begin();
fb[poz] = 1;
rb.erase({val, poz});
ra.erase({v[poz].a, poz});
} else if(v[i].a < v[i].b) {
fa[i] = 0;
auto [val, poz] = *ra.begin();
fa[poz] = 1;
ra.erase({val, poz});
rb.erase({v[poz].b, poz});
} else {
fa[i] = 0;
auto [val, poz] = *ra.begin();
fa[poz] = 1;
ra.erase({val, poz});
rb.erase({v[poz].b, poz});
}
}
}
long long ans = 0;
for(int i = 1; i <= n; i++) {
// cout << fa[i] << " " << fb[i] << '\n';
ans += fa[i] * v[i].a + fb[i] * v[i].b;
}
cout << -ans;
return 0;
}
