#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e18;
struct E {
int t, r;
ll c, w;
};
void add(vector<vector<E>> &g, int u, int v, ll c, ll 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<ll, ll> mcmf(vector<vector<E>> &g, int s, int t) {
int n = g.size();
ll f = 0, c = 0;
vector<ll> p(n, 0);
while (true) {
priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<>> q;
vector<ll> d(n, INF);
vector<int> pv(n, -1), pe(n, -1);
d[s] = 0;
q.push({0, s});
while (!q.empty()) {
auto [dist, u] = q.top();
q.pop();
if (dist > d[u]) continue;
for (int i = 0; i < g[u].size(); ++i) {
E &e = g[u][i];
if (e.c > 0 && d[e.t] > d[u] + e.w + p[u] - p[e.t]) {
d[e.t] = d[u] + e.w + p[u] - p[e.t];
pv[e.t] = u;
pe[e.t] = i;
q.push({d[e.t], e.t});
}
}
}
if (d[t] == INF) break;
for (int i = 0; i < n; ++i) if (d[i] < INF) p[i] += d[i];
ll af = INF, v = t;
while (v != s) {
int u = pv[v], i = pe[v];
af = min(af, g[u][i].c);
v = u;
}
f += af;
c += af * p[t];
v = t;
while (v != s) {
int u = pv[v], i = pe[v];
g[u][i].c -= af;
g[v][g[u][i].r].c += af;
v = u;
}
}
return {f, c};
}
int main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
int n, m, s;
cin >> n >> m >> s;
int src = 0, mus = 1, spo = 2, snk = 3 + n;
vector<vector<E>> g(4 + n);
vector<pair<int, int>> c(n);
for (int i = 0; i < n; ++i) cin >> c[i].first >> c[i].second;
add(g, src, mus, m, 0);
add(g, src, spo, s, 0);
for (int i = 0; i < n; ++i) {
int u = 3 + i;
add(g, mus, u, 1, -c[i].first);
add(g, spo, u, 1, -c[i].second);
add(g, u, snk, 1, 0);
}
auto res = mcmf(g, src, snk);
if (res.first != m + s) {
cout << "0";
return 0;
}
cout << -res.second;
}
