#include <bits/stdc++.h>
using namespace std;
const int maxn = 4e5+7;
pair<int, int> ppl[maxn];
int n, m, s;
int main(){
cin >> n >> m >> s;
for(int i = 0; i < n; i++){
cin >> ppl[i].first >> ppl[i].second;
}
sort(ppl, ppl+n, greater<pair<int,int>>());
int sol = 0;
priority_queue<pair<int, int>> musicbest;
priority_queue<pair<int, int>> remsports;
set<int> rmsprts;
for(int i = 0; i < m; i++){
sol+=ppl[i].first;
musicbest.push({ppl[i].second-ppl[i].first, i});
}
for(int i = m; i < n; i++){
remsports.push({ppl[i].second, i});
rmsprts.insert(i);
}
while(s--){
while(!remsports.empty() and rmsprts.count(remsports.top().second)){
remsports.pop();
}
if(remsports.empty() or (!musicbest.empty() and musicbest.top().first + ppl[*rmsprts.begin()].first > remsports.top().first)){
sol += musicbest.top().first + ppl[*rmsprts.begin()].first;
musicbest.pop();
musicbest.push({ppl[*rmsprts.begin()].second - ppl[*rmsprts.begin()].first, *rmsprts.begin()});
rmsprts.erase(rmsprts.begin());
} else {
sol += remsports.top().first;
rmsprts.erase(remsports.top().second);
remsports.pop();
}
}
cout << sol << '\n';
}
