#include <bits/stdc++.h>
using namespace std;
template <class A>
void pr(A a) {
  cout << a;
  cout << '\n';
}
template <class A, class B>
void pr(A a, B b) {
  cout << a << ' ';
  pr(b);
}
template <class A, class B, class C>
void pr(A a, B b, C c) {
  cout << a << ' ';
  pr(b, c);
}
template <class A, class B, class C, class D>
void pr(A a, B b, C c, D d) {
  cout << a << ' ';
  pr(b, c, d);
}
template <class A>
void PR(A a, long long n) {
  for (long long i = (long long)(0); i < (long long)(n); i++) {
    if (i) cout << ' ';
    cout << a[i];
  }
  cout << '\n';
}
long long check(long long n, long long m, long long x, long long y) {
  return x >= 0 && x < n && y >= 0 && y < m;
}
const long long MAX = 1e9 + 7, MAXL = 1LL << 61, dx[4] = {-1, 0, 1, 0},
                dy[4] = {0, 1, 0, -1};
void Main() {
  long long n, x, y;
  cin >> n >> x >> y;
  pair<long long, long long> a[n];
  for (long long i = (long long)(0); i < (long long)(n); i++)
    cin >> a[i].first >> a[i].second;
  priority_queue<pair<long long, long long> > que;
  long long sum = 0, d[n];
  for (long long i = (long long)(0); i < (long long)(n); i++) {
    que.push(pair<long long, long long>(a[i].first - a[i].second, i));
    sum += a[i].second;
    d[i] = a[i].first - a[i].second;
  }
  set<int> s;
  long long k = -1;
  for (long long i = (long long)(0); i < (long long)(min(n, y)); i++) {
    pair<long long, long long> p = que.top();
    que.pop();
    if (p.first <= 0) {
      k = -1;
      break;
    }
    k = p.second;
    s.insert(p.second);
    sum += p.first;
  }
  long long ans = sum;
  if (y) {
    for (long long i = (long long)(0); i < (long long)(n); i++) {
      long long c = sum - a[i].second;
      if (s.count(i))
        c -= d[i];
      else if (k >= 0)
        c -= d[k];
      long long z = a[i].first;
      for (long long j = (long long)(0); j < (long long)(x); j++) z *= 2;
      c += z;
      ans = max(ans, c);
    }
  }
  pr(ans);
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  Main();
  return 0;
}
