#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define pb(e) push_back(e)
#define sv(a) sort(a.begin(),a.end())
#define sa(a,n) sort(a,a+n)
#define mp(a,b) make_pair(a,b)
#define vf first
#define vs second
#define ar array
#define all(x) x.begin(),x.end()
const int inf = 0x3f3f3f3f;
const int mod = 1000000007;
const double PI=3.14159265358979323846264338327950288419716939937510582097494459230;
bool remender(ll a , ll b){return a%b;}
void solve(){
int n;
cin >> n;
int m , k;
cin >> m >> k;;
ll a[n] , b[n];
vector<pair<int,int>> v;
for(int i = 0; i < n; i++){
cin >> a[i] >> b[i];
v.pb(mp(a[i] - b[i] , i));
}
sv(v);
reverse(all(v));
ll pre[n] , suf[n];
memset(pre , 0 , sizeof pre);
memset(suf , 0 , sizeof suf);
ll sum = 0;
if(m > 0){
priority_queue<ll , vector<ll> , greater<ll> > q;
for(int i = 0; i < m; i++){
sum += a[v[i].vs];
q.push(a[v[i].vs]);
}
pre[m - 1] = sum;
for(int i = m; i < n; i++){
if(q.top() < a[v[i].vs]){
sum -= q.top();
q.pop();
q.push(a[v[i].vs]);
sum += a[v[i].vs];
}
pre[i] = sum;
}
}
sum = 0;
if(k > 0){
priority_queue<ll , vector<ll> , greater<ll> > pq;
for(int i = n - 1; i >= n - k; i--){
pq.push(b[v[i].vs]);
sum += b[v[i].vs];
}
suf[n - k] = sum;
for(int i = n - (k + 1); i >= 0; i--){
if(pq.top() < b[v[i].vs]){
sum -= pq.top();
sum += b[v[i].vs];
pq.pop();
pq.push(b[v[i].vs]);
}
suf[i] = sum;
}
}
ll ans = 0;
if(m == 0){
ans = suf[0];
}
else if(k == 0){
ans = pre[n - 1];
}
else {
for(int i = m - 1; i < n - k; i++){
ans = max(ans , pre[i] + suf[i + 1]);
}
}
cout << ans << '\n';
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
//freopen("school.in", "r", stdin);
//freopen("school.out", "w", stdout);
//int t;cin >> t;while(t--)
solve();
return 0;
}
