cf976e Well played!

#include <algorithm>
#include <iostream>
#include <cstdio>
using namespace std;
typedef long long ll;
int n, a, b;
ll ans, tmp;
struct Node{
    ll hp, dm;
}nd[200005];
bool cmp(Node x, Node y){
    return x.hp-x.dm>y.hp-y.dm;
}
int main(){
    cin>>n>>a>>b;
    for(int i=1; i<=n; i++)
        scanf("%I64d %I64d", &nd[i].hp, &nd[i].dm);
    sort(nd+1, nd+1+n, cmp);
    for(int i=1; i<=n; i++)
        if(i<=b)    ans += max(nd[i].hp, nd[i].dm);
        else    ans += nd[i].dm;
    if(b==0){
        printf("%I64d\n", ans);
        return 0;
    }
    tmp = ans;
    for(int i=1; i<=n; i++){
        ll qaq=tmp;
        if(i<=b){
            qaq -= max(nd[i].hp, nd[i].dm);
            qaq += max(nd[i].dm, max(nd[i].hp*(1<<a), nd[i].dm));
            ans = max(ans, qaq);
        }
        else{
            qaq -= nd[i].dm;
            qaq += max(nd[i].dm, max(nd[i].hp*(1<<a), nd[i].dm));
            qaq -= max(nd[b].hp, nd[b].dm);
            qaq += nd[b].dm;
            ans = max(ans, qaq);
        }
    }
    cout<<ans<<endl;
    return 0;
}