#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int INF = INT32_MAX;
struct E {
int to, rev, cap, cost;
};
vector<vector<E>> g;
inline void add_e(int u, int v, int c, int w) {
g[u].push_back({v, (int)g[v].size(), c, w});
g[v].push_back({u, (int)g[u].size() - 1, 0, -w});
}
pair<int, ll> mcf(int n, int src, int sink, int mf) {
vector<int> pot(n, 0), dist(n, 0), prevv(n, -1), preve(n, -1);
int flow = 0;
ll cost = 0;
while (flow < mf) {
fill(dist.begin(), dist.end(), INF);
dist[src] = 0;
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
pq.emplace(0, src);
while (!pq.empty()) {
auto [d, u] = pq.top();
pq.pop();
if (d > dist[u]) continue;
for (int i = 0; i < g[u].size(); ++i) {
E &e = g[u][i];
if (e.cap > 0 && dist[e.to] > dist[u] + e.cost + pot[u] - pot[e.to]) {
dist[e.to] = dist[u] + e.cost + pot[u] - pot[e.to];
prevv[e.to] = u;
preve[e.to] = i;
pq.emplace(dist[e.to], e.to);
}
}
}
if (dist[sink] == INF) break;
for (int i = 0; i < n; i++) if (dist[i] < INF) pot[i] += dist[i];
int add_flow = mf - flow, v = sink;
while (v != src) {
add_flow = min(add_flow, g[prevv[v]][preve[v]].cap);
v = prevv[v];
}
flow += add_flow;
cost += (ll)add_flow * pot[sink];
v = sink;
while (v != src) {
E &e = g[prevv[v]][preve[v]];
e.cap -= add_flow;
g[v][e.rev].cap += add_flow;
v = prevv[v];
}
}
return {flow, cost};
}
int main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
int n, m, s;
cin >> n >> m >> s;
int nodes = 3 + n + 1;
int src = 0, mus = 1, spo = 2, sink = 3 + n;
g.assign(nodes, vector<E>());
for (int i = 0; i < n; i++) {
int a, b;
cin >> a >> b;
int city = 3 + i;
add_e(mus, city, 1, -a);
add_e(spo, city, 1, -b);
add_e(city, sink, 1, 0);
}
add_e(src, mus, m, 0);
add_e(src, spo, s, 0);
pair<int, ll> res = mcf(nodes, src, sink, m + s);
cout << -res.second;
}
