/* AUTHOR: TUAN ANH - BUI */
// ~~ icebear ~~
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
template<class X, class Y>
bool minimize(X &x, const Y &y) {
if (x > y) return x = y, true;
return false;
}
template<class X, class Y>
bool maximize(X &x, const Y &y) {
if (x < y) return x = y, true;
return false;
}
#define FOR(i,a,b) for(int i=(a); i<=(b); ++i)
#define FORR(i,a,b) for(int i=(a); i>=(b); --i)
#define REP(i, n) for(int i=0; i<(n); ++i)
#define RED(i, n) for(int i=(n)-1; i>=0; --i)
#define MASK(i) (1LL << (i))
#define BIT(S, i) (((S) >> (i)) & 1)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define task "icebear"
/*END OF TEMPLATE. ICEBEAR AND THE CAT WILL WIN VOI26 */
const int MOD = 1e9 + 7;
const int inf = (int)1e9 + 27092008;
const ll INF = (ll)1e18 + 27092008;
const int N = 3e5 + 5;
int n, m, k;
ii a[N];
void init(void) {
cin >> n >> m >> k;
FOR(i, 1, n) cin >> a[i].fi >> a[i].se;
}
void process(void) {
sort(a + 1, a + n + 1, [&](const ii &x, const ii &y){
return x.fi - x.se < y.fi - y.se;
});
vector<ll> pf(n + 5, 0), sf(n + 5, 0);
priority_queue<int, vector<int>, greater<int>> Q;
FOR(i, 1, n) {
Q.push(a[i].se);
pf[i] = pf[i - 1] + a[i].se;
if (Q.size() > k) {
pf[i] -= Q.top();
Q.pop();
}
}
while(!Q.empty()) Q.pop();
FORR(i, n, 1) {
Q.push(a[i].fi);
sf[i] = sf[i + 1] + a[i].fi;
if (Q.size() > m) {
sf[i] -= Q.top();
Q.pop();
}
}
ll ans = 0;
FOR(i, k, n - m) maximize(ans, pf[i] + sf[i+1]);
cout << ans;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
if (fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
int tc = 1;
// cin >> tc;
while(tc--) {
init();
process();
}
return 0;
}
