#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll NEG = LLONG_MIN/4;
int n,m,s;
ll a[300005],b[300005];
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> m >> s;
vector<pair<ll,ll>> v(n);
for(int i=0;i<n;i++)
cin>>v[i].first>>v[i].second;
sort(v.begin(), v.end(), [](const pair<ll,ll>& x,const pair<ll,ll>& y)
{
return (x.first - x.second) > (y.first - y.second);
});
for(int i=0;i<n;i++)
{
a[i]=v[i].first;
b[i]=v[i].second;
}
vector<ll> dp1(n, NEG), dp2(n, NEG);
if(m==0)
{
for(int i=0;i<n;i++) dp1[i]=0;
}
else
{
priority_queue<ll, vector<ll>, greater<ll>> pq;
ll sum=0;
for(int i=0;i<n;i++)
{
pq.push(a[i]); sum += a[i];
if(pq.size()>m)
{
sum -= pq.top();
pq.pop();
}
if(pq.size()==m) dp1[i]=sum;
}
}
if(s==0)
{
for(int i=0;i<n;i++) dp2[i]=0;
}
else
{
priority_queue<ll, vector<ll>, greater<ll>> pq;
ll sum=0;
for(int i=n-1;i>=0;i--)
{
pq.push(b[i]); sum += b[i];
if(pq.size()>s)
{
sum -= pq.top();
pq.pop();
}
if(pq.size()==s) dp2[i]=sum;
}
}
ll ans = NEG;
if(m==0)
{
if(dp2[0]!=NEG) ans = max(ans, dp2[0]);
}
else if(s==0)
{
if(dp1[n-1]!=NEG) ans = max(ans, dp1[n-1]);
}
else
{
int L = m-1, R = n-s-1;
if(L<=R)
{
for(int i=L;i<=R;i++)
{
if(dp1[i]!=NEG && dp2[i+1]!=NEG) ans = max(ans, dp1[i]+dp2[i+1]);
}
}
}
if(ans==NEG) ans=0;
cout<<ans;
}
