#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define oke cout << "Yes" << '\n';
#define dame cout << "No" << '\n';
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
using Hai2 = vector<vector<ll>>;
using HaiW = vector<vector<pair<ll,ll>>>;
using HaiB = vector<vector<bool>>;
using Hai3 = vector<vector<vector<ll>>>;

int main() {
	cout << fixed << setprecision(15);
    ll N,A,B;
    cin>>N>>A>>B;
    vector<pair<ll,ll>>Z(N);
    rep(i,N){
        ll a,b;
        cin>>a>>b;
        Z[i]={b,a};
    }
    sort(all(Z));
    ll ans=0;
    ll a=0,b=0;
    rep(i,N){
        ll c,d;
        tie(d,c)=Z[i];
        if(a+c<=A && b+d<=B){
            ans++;
            a+=c;
            b+=d;
        }
    }
    cout<<ans<<endl;
}