#include<iomanip>
#include<limits>
#include<thread>
#include<utility>
#include<iostream>
#include<string>
#include<algorithm>
#include<set>
#include<map>
#include<vector>
#include<stack>
#include<queue>
#include<cmath>
#include<numeric>
#include<cassert>
#include<random>
#include<chrono>
#include<unordered_set>
#include<unordered_map>
#include<fstream>
#include<list>
#include<functional>
#include<bitset>
#include<complex>
#include<tuple>
using namespace std;
typedef unsigned long long int ull;
typedef long long int ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pi;
typedef pair<double,double> pd;
typedef pair<double,ll> pdl;
#define F first
#define S second
const ll E=1e18+7;
const ll MOD=1000000007;




class comb{
private:
    ll mod;
    ll mx;
    vector<ll> F;
    vector<ll> FR;
    
public:
    comb(ll mod=1000000007,ll mx=1000000):mod(mod),mx(mx),F(mx+1,1),FR(mx+1,1){
        mk_F();
    }
    
    ll mod_pow(ll a,ll x){
        a%=mod;
        ll ans=1;
        while(x>0){
            if(x&1){ans*=a; ans%=mod;}
            a*=a;
            a%=mod;
            x>>=1;
        }
        return ans;
    }
    
    pll Ex_gcd(ll a,ll b){
        if(b==0){return {1,0};}
        pll ret=Ex_gcd(b,a%b);
        ret.F-=a/b*ret.S;
        return {ret.S,ret.F};
    }
    
    ll prime_R(ll a){
        return mod_pow(a,mod-2);
    }
    
    ll R(ll a){
        ll ret=Ex_gcd(a,mod).F;
        ret%=mod;
        if(ret<0){ret+=mod;}
        return ret;
    }
    
    void mk_F(){
        for(ll i=1;i<=mx;i++){F[i]=F[i-1]*i%mod; FR[i]=R(F[i]);}
    }
    
    ll c(ll n,ll k){
        if(n<k){return 0;}
        if(n==k || k==0){return 1;}
        return F[n]*FR[n-k]%mod*FR[k]%mod;
    }
    
    //mod must be prime
    ll Lucas_C(ll n,ll m){
        ll ret=1;
        while(n>0 || m>0){
            ret*=c(n%mod,m%mod);
            ret%=mod;
            n/=mod; m/=mod;
        }
        return ret;
    }
    
    ll Stirling(ll n,ll k){
        ll ret=0;
        for(ll i=1;i<=k;i++){
            if((k-i)%2){ret-=c(k,i)*mod_pow(i,n)%mod;}
            else{ret+=c(k,i)*mod_pow(i,n)%mod;}
            ret%=mod;
        }
        ret*=R(F[k]);
        ret%=mod;
        if(ret<0){ret+=mod;}
        return ret;
    }
    
    ll Bell(ll n,ll k){
        ll ret=0;
        for(ll i=1;i<=k;i++){ret+=Stirling(n,i); ret%=mod;}
        return ret;
    }
};





vector<pll> uft;

ll parent(ll w){
    if(uft[w].F==w){return w;}
    return uft[w].F=parent(uft[w].F);
}

void merge(ll a,ll b){
    if(parent(a)==parent(b)){return;}
    if(uft[parent(a)].S<uft[parent(b)].S){swap(a,b);}
    uft[parent(a)].S+=uft[parent(b)].S;
    uft[parent(b)].F=parent(a);
}


int main(){
    comb C;
    ll n,x,y;
    cin>>n>>x>>y;
    vector<vector<pll>> A(n);
    vector<pll> a(n);
    uft.resize(n);
    for(int i=0;i<n;i++){uft[i]={i,1};}
    for(int i=0;i<n;i++){
        ll c,w;
        cin>>c>>w;
        c--;
        a[i]={c,w};
        A[c].push_back({w,i});
    }
    for(int i=0;i<n;i++){sort(A[i].begin(),A[i].end());}
    sort(A.begin(),A.end());
    for(auto &I:A){
        for(auto &T:I){
            if(T.F+I[0].F<=x){merge(T.S,I[0].S);}
        }
    }
    ll w=0;
    while(A[w].size()==0){w++;}
    for(ll i=w+1;i<n;i++){
        for(auto &T:A[i]){
            if(T.F+A[w][0].F<=y){merge(A[w][0].S,T.S);}
        }
    }
    for(ll i=w+1;i<n;i+=MOD){
        for(auto &T:A[w]){
            if(A[i][0].F+T.F<=y){merge(A[i][0].S,T.S);}
        }
    }
    vector<map<ll,ll>> M(n);
    for(int i=0;i<n;i++){M[parent(i)][a[i].F]++;}
    ll ans=1;
    for(int i=0;i<n;i++){
        if(parent(i)!=i){continue;}
        ll cnt=uft[parent(i)].S;
        for(auto it=M[i].begin();it!=M[i].end();it++){
            ans*=C.c(cnt,it->second);
            cnt-=it->second;
            ans%=MOD;
        }
    }
    cout<<ans<<endl;
    
    
    return 0;
}


Measured memory_bytes: 54272