#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define f first
#define s second
#define sz(a) (int)((a).size())
#define all(a) (a).begin(), (a).end()
#define uni(a) sort(all(a)), (a).resize(unique(all(a)) - (a).begin())
typedef pair <int, int> ii;
const int N = 3e5 + 1;
priority_queue <int, vector <int>, greater <int>> pq;
int n, m, s;
ll pre[N], suf[N], ans, cur;
ii a[N];
void solve() {
cin >> n >> m >> s;
for (int i = 1; i <= n; i++) {
cin >> a[i].f >> a[i].s;
}
sort(a + 1, a + n + 1, [&](ii a, ii b){return a.f - a.s > b.f - b.s;});
for (int i = 1; i <= n; i++) {
cur += a[i].f; pq.push(a[i].f);
while (sz(pq) > m) {
int top = pq.top(); pq.pop();
cur -= top;
}
pre[i] = max(pre[i], cur);
}
while (sz(pq)) pq.pop();
cur = 0;
for (int i = n; i >= 1; i--) {
cur += a[i].s; pq.push(a[i].s);
while (sz(pq) > s) {
int top = pq.top(); pq.pop();
cur -= top;
}
suf[i] = max(suf[i + 1], cur);
}
for (int i = m; i + s <= n; i++) {
ans = max(ans, pre[i] + suf[i + 1]);
}
cout << ans << '\n';
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
// freopen("a.inp", "r", stdin);
// freopen("a.out", "w", stdout);
int t = 1;
// cin >> t;
while (t--) {
solve();
}
return 0;
}
