#include <bits/stdc++.h>
#define x first
#define y second
#define pb push_back
#define mp make_pair
#define up_b upper_bound
#define low_b lower_bound
#define sz(x) (int)x.size()
#define all(v) v.begin(),v.end()
#define boost ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<int,ll> pil;
typedef pair<ll,int> pli;
typedef pair<ll,ll> pll;
const ll INF = 1e18;
const ll inf = 1e9;
const int mod = 998244353;
const int dx[4] = {0, 0, 1, -1};
const int dy[4] = {1, -1, 0, 0};
const int N = 3e5+5;
const int M = 1e5+1;
int u[N],u2[N];
int a[N],b[N];
pii c[N];
int main(){
int n,m,s;
cin>>n>>m>>s;
for(int i=1;i<=n;i++){
cin>>a[i]>>b[i];
c[i]=mp(a[i]-b[i],i);
}
sort(c+1,c+n+1);
reverse(c+1,c+n+1);
ll ans1=0,ans2=0;
for(int i=1;i<=m;i++){
ans1+=a[c[i].y];
u[c[i].y]=1;
}
vector<int>v;
for(int i=1;i<=n;i++){
if(!u[i]){
v.pb(b[i]);
}
}
sort(all(v));
reverse(all(v));
for(int i=0;i<s;i++){
ans1+=v[i];
}
v.clear();
for(int i=n;i>=n-s+1;i--){
ans2+=b[c[i].y];
u2[c[i].y]=1;
}
for(int i=1;i<=n;i++){
if(!u2[i]){
v.pb(a[i]);
}
}
sort(all(v));
reverse(all(v));
for(int i=0;i<m;i++){
ans2+=v[i];
}
cout<<max(ans1,ans2);
}
