#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int maxn=3e5+5;
int n,s[2],a[maxn],b[maxn];
ll cep[maxn],sag[maxn],nw;
vector<pair<int,int>>v;
vector<int>a_s,b_s;
multiset<int>m;
ll ans;
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
cin >> n >> s[0] >> s[1];
for(int i = 1;i <= n;i++){
cin >> a[i] >> b[i];
a_s.push_back(-a[i]);
b_s.push_back(-b[i]);
v.push_back({a[i]-b[i],i});
}
sort(a_s.begin(),a_s.end());
sort(b_s.begin(),b_s.end());
if(s[0] == 0){
for(int i = 0;i < s[1];i++) ans -= b_s[i];
return cout<<ans,0;
}
if(s[1]==0){
for(int i = 0;i < s[0];i++) ans -= a_s[i];
return cout<<ans,0;
}
sort(v.begin(),v.end());
reverse(v.begin(),v.end());
for(int i = 0;i < s[0];i++) m.insert(a[v[i].second]),nw += a[v[i].second],cep[i]=-1e9;
cep[s[0]-1] = nw;
for(int i = s[0];i < (int)v.size();i++){
if(!m.empty() and *m.begin() < a[v[i].second]){
nw -= *m.begin();
nw += a[v[i].second];
m.erase(m.begin());
m.insert(a[v[i].second]);
}
cep[i] = nw;
}
m.clear(); nw = 0;
for(int i = (int)v.size()-1;i >= (int)v.size()-s[1];i--) m.insert(b[v[i].second]),nw += b[v[i].second],sag[i]=-1e9;
sag[(int)v.size() - s[1]] = nw;
for(int i = (int)v.size()-s[1]-1;i >= 0;i--){
if(!m.empty() and *m.begin() < b[v[i].second]){
nw -= *m.begin();
nw += b[v[i].second];
m.erase(m.begin());
m.insert(b[v[i].second]);
}
sag[i] = nw;
}
for(int i = 0;i < (int)v.size() - 1;i++) ans = max(ans,cep[i]+sag[i+1]);
cout<<ans;
}
