#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define ff(i,a,b) for(int i=a;i<=b;i++)
#define fb(i,b,a) for(int i=b;i>=a;i--)
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef pair<int,int> pii;
const int maxn = 300005;
const int inf = 1e9 + 5;
template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
// os.order_of_key(k) the number of elements in the os less than k
// *os.find_by_order(k) print the k-th smallest number in os(0-based)
int n, M, S;
pii niz[maxn];
int main()
{
ios::sync_with_stdio(false);
cout.tie(nullptr);
cin.tie(nullptr);
cin >> n >> M >> S;
ff(i,1,n)cin >> niz[i].fi >> niz[i].se;
sort(niz + 1, niz + n + 1);
reverse(niz + 1, niz + n + 1);
multiset<int> C;
multiset<pii> A, B;
ll rez = 0;
ff(i,1,M) {
rez += niz[i].fi;
C.insert(niz[i].se - niz[i].fi);
}
ff(i,M + 1, n) {
A.insert({niz[i].fi, i});
B.insert({niz[i].se, i});
}
ff(i,1,S) {
pii X = *B.rbegin();
pii Y = {*C.rbegin() + A.rbegin()->fi, A.rbegin()->se};
if(X.fi >= Y.fi) {
rez += X.fi;
B.erase(B.find(X));
A.erase(A.find({niz[X.se].fi, X.se}));
} else {
rez += Y.fi;
C.erase(C.find(*C.rbegin()));
B.erase(B.find({niz[Y.se].se, Y.se}));
A.erase(A.find(*A.rbegin()));
C.insert(niz[Y.se].se - niz[Y.se].fi);
}
}
cout << rez << endl;
return 0;
}
/**
7 2 3
9 8
10 6
3 5
1 7
5 7
6 3
5 4
3 1 1
5 2
4 1
6 4
// probati bojenje sahovski ili slicno
**/
