#include <bits/stdc++.h>
using namespace std;
#define range(i, l, r) for (int i = (int)(l); i < (int)(r); (i) += 1)
#define rrange(i, l, r) for (int i = (int)(r)-1; i >= (int)(l); (i) -= 1)
template <typename T1, typename T2> inline void chmax(T1 &a, T2 b) { a = (a > b ? a : b); }
template <typename T1, typename T2> inline void chmin(T1 &a, T2 b) { a = (a < b ? a : b); }
template <typename T1, typename T2> ostream &operator<<(ostream &os,const pair<T1,T2> &p) { os<<p.first<<' '<<p.second; return os;}
template <typename T> ostream &operator<<(ostream &os,const vector<T> &v) { range(i,0,v.size()) {os<<(i?" ":"")<<v[i];} return os;}
using ull = unsigned long long;
using ll = long long;
using Pll = pair<ll, ll>;
using P = pair<int, int>;
constexpr ll INF64 = INT64_MAX / 2;
constexpr int INF32 = INT32_MAX / 2;
constexpr int dy[] = {0,-1,1,0,-1,1,-1,1};
constexpr int dx[] = {-1,0,0,1,-1,-1,1,1};
constexpr int mod998244353 = 998244353;
constexpr int mod1000000007 = (int)1e9 + 7;
constexpr char newl = '\n';

int main() {
  int n,D,H;
  cin>>n>>D>>H;

  double ans=0.0;
  vector<P> dh(n);
  range(i,0,n){
    auto &[d,h]=dh[i];
    cin>>d>>h;
    chmax(ans,(double)(0-d)*(H-h)/(D-d) + h);
  }
  cout<<fixed<<setprecision(10);
  cout<<ans<<endl;
}
#include <bitset>
#include <iostream>
#include <iomanip>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <valarray>

// alias, using declaration
using llint = long long; using ldouble = long double;
template <class T = llint> using vector = std::vector<T>;
template <class T = llint> using deque = std::deque<T>;
template <class T = llint, class U = llint, class... V> using map = std::map<T, U, V...>;
template <class T = llint, class... U> using set = std::set<T, U...>;
template <class T = llint, class U = llint> using umap = std::unordered_map<T, U>;
template <class T = llint> using uset = std::unordered_set<T>;
template <class T = llint, class U = T> using pair = std::pair<T, U>;
template <class T = llint> using varray = std::valarray<T>;
template <class T = llint, class... U> using pqueue = std::priority_queue<T, U...>;
using std::array; using std::bitset; using std::string; using std::tuple;

// constant
constexpr llint INF = 0x3FFFFFFFFFFFFFFF;
constexpr llint INVALID = 0x8000000000000000;

namespace io {
  // in
  template <class... T, size_t... S> auto in(std::index_sequence<S...>) {tuple<T...> t; (..., (std::cin >> std::get<S>(t))); return t;}
  template <class... T, size_t... S> auto in(std::index_sequence<S...>, size_t n) {tuple<vector<T>...> t{vector<T>(n)...}; for (size_t i = 0; i < n; i++) (..., (std::cin >> std::get<S>(t)[i])); return t;}
  template <size_t N, class T = llint, class... U> auto in() {static_assert(N >= 1); if constexpr (N > 1) return in<N - 1, T, T, U...>(); else return in<T, U...>(std::index_sequence_for<T, U...>());}
  template <size_t N, class T = llint, class... U> auto in(size_t n) {static_assert(N >= 1); if constexpr (N > 1) return in<N - 1, T, T, U...>(n); else return in<T, U...>(std::index_sequence_for<T, U...>(), n);}
  template <size_t N, class T = llint> auto in(size_t n, size_t m) {static_assert(N == 1); vector<vector<T>> v(n, vector<T>(m)); for (auto&& vi : v) for (auto&& vij : vi) std::cin >> vij; return std::make_tuple(v);}
  // out
  template <class T, class... U> void out(const T& a, const U&... b) {std::cout << a << (sizeof...(b) ? " " : "\n"); if constexpr (sizeof...(b)) out(b...);}
  template <class T, class U = const char*> void out(const vector<T>& a, U d = " ") {for (auto&& b : a) std::cout << b << (&b != &a.back() ? d : "\n");}
}

int main() {
  // input
  auto [a, b, c] = io::in<3>();

  // solve
  auto result = (7 - a) + (7 - b) + (7 - c);

  // output
  io::out(result);
}