#include <bits/stdc++.h>
using namespace std;
#define file ""
#define mp make_pair
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define getbit(x, i) (((x) >> (i)) & 1)
#define bit(x) (1LL << (x))
#define popcount __builtin_popcountll
mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) {
return l + rd() % (r - l + 1);
}
const int N = 1e6 + 5;
const int mod = (int)1e9 + 7; // 998244353;
const int lg = 25; // lg + 1
const int oo = 1e9;
const long long ooo = 1e18;
template<class X, class Y> bool mini(X &a, Y b) {
return a > b ? (a = b, true) : false;
}
template<class X, class Y> bool maxi(X &a, Y b) {
return a < b ? (a = b, true) : false;
}
void add(int &a, int b) {
a += b;
if (a >= mod) a -= mod;
if (a < 0) a += mod;
}
int n, m, s;
pair<int, int> a[N];
int f[N], g[N];
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
// freopen(file".inp", "r", stdin);
// freopen(file".out", "w", stdout);
cin >> n >> m >> s;
for (int i = 1; i <= n; ++i)
cin >> a[i].fi >> a[i].se;
sort(a + 1, a + n + 1, [&] (pair<int, int> x, pair<int, int> y) {
return x.fi - x.se > y.fi - y.se;
});
priority_queue<int, vector<int>, greater<int> > q;
for (int i = 1; i <= n; ++i) {
f[i] = f[i - 1] + a[i].fi;
q.push(a[i].fi);
if ((int) q.size() > m) {
f[i] -= q.top();
q.pop();
}
}
while (q.size()) q.pop();
for (int i = n; i >= 1; --i) {
g[i] = g[i + 1] + a[i].se;
q.push(a[i].se);
if ((int) q.size() > s) {
g[i] -= q.top();
q.pop();
}
}
int res = 0;
for (int i = m; i <= n - s; ++i) res = max(res, f[i] + g[i + 1]);
cout << res;
return 0;
}
/*
*/
