#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
using ll = long long; using ull = unsigned long long;
using pii = pair<int, int>; using vi = vector<int>; using vvi = vector<vi>; using vvvi = vector<vvi>;
using pll = pair<ll, ll>; using vl = vector<ll>; using vvl = vector<vl>; using vvvl = vector<vvl>;
using pdd = pair<double, double>; using vd = vector<double>; using vvd = vector<vd>; using vvvd = vector<vvd>;
using pbb = pair<bool, bool>; using vb = vector<bool>; using vvb = vector<vb>; using vvvb = vector<vvb>;
using pss = pair<string, string>; using vs = vector<string>; using vvs = vector<vs>; using vvvs = vector<vvs>;
#define repeat(counter, start, goal, step) for (int counter = (int)(start); counter < (int)(goal); counter += step)
#define rep(counter, times) repeat(counter, 0, times, 1)
#define rep2(counter, start, goal) repeat(counter, start, goal, 1)
#define rep0(times) repeat(counter, 0, times, 1)
#define rrepeat(counter, start, goal, step) for (int counter = (int)(start); counter > (int)(goal); counter -= step)
#define rep3(counter, start, goal) rrepeat(counter, start, goal, 1)
#define rrep(counter, start, goal) rrepeat(counter, start - 1, goal - 1, 1)
#define all(container) begin(container), end(container)
template <typename T> bool chmax(T &x, const T &y) { if (x < y) { x = y; return true; } return false; }
template <typename T> bool chmin(T &x, const T &y) { if (x > y) { x = y; return true; } return false; }
void yn(bool flag) { cout << (flag ? "yes" : "no") << "\n"; }
void Yn(bool flag) { cout << (flag ? "Yes" : "No") << "\n"; }
void YN(bool flag) { cout << (flag ? "YES" : "NO") << "\n"; }
void set_prec(const int &digits) { cout << fixed << setprecision(digits); cerr << fixed << setprecision(digits); }
template <typename T> void pr(const T &obj) { cerr << obj; }
template <typename T, typename ...Ts> void pr(const T &first, const Ts &...rest) { pr(first); pr(", "); pr(rest...); }
template <typename S, typename T> void pr(const pair<S, T> &pair) { pr("("); pr(pair.first); pr(", "); pr(pair.second); pr(")"); }
template <typename T> void pr(const vector<T> &vec) { pr("{"); for (T obj : vec) { pr(obj); pr(", "); } pr("}"); }
template <typename T> void pr(const vector<vector<T>> &vv) { pr("\n"); rep(index, vv.size()) { pr("["); pr(index); pr("]: "); pr(vv[index]); pr("\n"); } }
template <typename T> void pr(const set<T> &vec) { pr("{"); for (T obj : vec) { pr(obj); pr(", "); } pr("}"); }
template <typename S, typename T> void pr(const map<S, T> &map) { pr("{"); for (pair<S, T> pair : map) { pr("("); pr(pair.first); pr(": "); pr(pair.second); pr("), "); } pr("}"); }
#define db(obj) cerr << #obj << ": "; pr(obj); cerr << " "
#define dl(obj) db(obj); cerr << "\n";
#define dm(...) cerr << "(" << #__VA_ARGS__ << "): ("; pr(__VA_ARGS__); cerr << ") "
#define dml(...) dm(__VA_ARGS__); cerr << "\n"
// #include <atcoder/all>
// using namespace atcoder;
// const ll MOD = 1000000007;
// const ll MOD = 998244353;

int main() {
	int N, S, D; cin >> N >> S >> D;
	vi X(N), Y(N);
	rep(i, N) cin >> X[i] >> Y[i];
	bool f = false;
	rep(i, N) if (X[i] < S && Y[i] > D) f = true;
	Yn(f);
}
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int mod=1e9+7;
double dp[105][105][105];
double dfs(int a,int b,int c,int cnt){
    if(a==100||b==100||c==100){
        return cnt;
    }
    if(dp[a][b][c]) {
        return dp[a][b][c];
    }
    dp[a][b][c]=(a*dfs(a+1,b,c,cnt+1)+b*dfs(a,b+1,c,cnt+1)+c*dfs(a,b,c+1,cnt+1))*1.0/(a+b+c);
    return dp[a][b][c];
}
void solve(){
    int a,b,c;
    cin>>a>>b>>c;
    printf("%.10f",dfs(a,b,c,0));
}
int main() {
    int _=1;
    while(_--){
        solve();
    }
    return 0;
}    