#include <bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
using namespace std;
bool cmp(pii& a, pii& b)
{
return a.f-a.s<b.f-b.s;
}
ll max(ll a, ll b)
{
if (a>b)
return a;
return b;
}
int main()
{
ios_base::sync_with_stdio(0);cin.tie(0);
int n,M,S;
cin>>n>>M>>S;
pii a[n+1];
for (int i=1;i<=n;++i)
cin>>a[i].f>>a[i].s;
sort(a+1,a+n+1,cmp);
ll sum=0,ans=0,b[n+2],c[n+2];
priority_queue<int,vector<int>,greater<int>> p,q;
for (int i=1;i<=n;++i)
{
sum+=a[i].s;
p.push(a[i].s);
if (i>S)
{
sum-=p.top();
p.pop();
}
b[i]=sum;
}
sum=0;
for (int i=n;i;--i)
{
sum+=a[i].f;
q.push(a[i].f);
if (n-i>=M)
{
sum-=q.top();
q.pop();
}
c[i]=sum;
}
b[0]=c[n+1]=0;
b[n+1]=b[n];
c[0]=c[1];
for (int i=0;i<=n;++i)
ans=max(ans,b[i]+c[i+1]);
cout<<ans;
}
