#include <bits/stdc++.h>
#define pb push_back
#define mk make_pair
#define fr first
#define sc second
using namespace std;
const int N = 3e5 + 5;
int n, x, y, must[N * 4];
pair <int, int> t[N * 4];
pair <int, int> a[N];
long long ans;
void push(int v, int tl, int tr)
{
t[v].fr += must[v];
if (tl != tr)
{
must[v + v] += must[v];
must[v + v + 1] += must[v];
}
must[v] = 0;
}
void upd (int l, int r, int val, int v = 1, int tl = 1, int tr = n)
{
push(v, tl, tr);
if (tl > r || l > tr) return;
if (l <= tl && tr <= r)
{
must[v] += val;
push(v, tl, tr);
return ;
}
int tm = (tl + tr) >> 1;
upd(l, r, val, v + v, tl, tm);
upd(l, r, val, v + v + 1, tm + 1, tr);
t[v] = max( t[v + v], t[v + v + 1] );
}
void build (int v = 1, int tl = 1, int tr = n)
{
if(tl == tr)
{
if (tl <= x)
t[v] = mk( -a[tl].fr + a[tl].sc + a[x + 1].fr, tl );
else
t[v] = mk( a[tl].sc, tl );
}
else
{
int tm = (tl + tr) >> 1;
build( v + v, tl, tm );
build( v + v + 1, tm + 1, tr );
t[v] = max(t[v + v], t[v + v + 1]);
}
}
set <int> st;
main()
{
cin >> n >> x >> y;
for (int i = 1; i <= n; i++)
{
scanf("%d%d", &a[i].fr, &a[i].sc);
}
sort( a + 1, a + n + 1, greater < pair <int, int> >() );
for (int i = 1; i <= x; i++)
ans += a[i].fr;
for (int i = x + 1; i <= n; i++)
st.insert(i);
build();
while(y--)
{
if ( st.count( t[1].sc ) )
{
int val = t[1].fr, ind = t[1].sc;
ans += t[1].fr;
upd( 1, x, -a[*st.begin()].fr );
upd( ind, ind, -1e9 - 7 );
st.erase(ind );
if (!st.empty())
upd( 1, x, +a[*st.begin()].fr );
}
else
{
int val = t[1].fr, ind = t[1].sc;
ans += t[1].fr;
upd( 1, x, -a[*st.begin()].fr );
upd( *st.begin(), *st.begin(), -1e9 - 7 );
st.erase(st.begin());
if (!st.empty())
upd( 1, x, +a[*st.begin()].fr );
upd( ind, ind, -1e9 - 7 );
}
}
cout << ans << endl;
}
/**
5 3 2
41 36
47 16
27 2
29 4
33 30
**/
