#include<bits/stdc++.h>
//ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
//clock_t start=clock();clock_t end=clock();cout<<(double)(end-start)/CLOCKS_PER_SEC<<endl;
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int ui;
typedef pair<int,int> pii;
typedef pair<pii,int> ppii;
typedef pair<int,pii> pipi;
typedef pair<ll,ll> pll;
typedef pair<pll,ll> ppll;
typedef pair<ll,pll> plpl;
typedef tuple<ll,ll,ll> tl;
typedef pair<double,double> pdd;
typedef vector<vector<ll>> mat;
ll mod=1000000007;
ll mod2=998244353;
ll mod3=1000003;
ll mod4=998244853;
ll mod5=1000000009;
ll inf=1LL<<60;
double pi=3.141592653589793238462643383279L;
double eps=1e-14;
#define rep(i,m,n) for(ll i=m;i<n;i++)
#define rrep(i,n,m) for(ll i=n;i>=m;i--)
#define srep(itr,st) for(auto itr=st.begin();itr!=st.end();itr++)
#define mrep(itr,mp) for(auto itr=mp.begin();itr!=mp.end();itr++)
#define Max(a,b) a=max(a,b)
#define Min(a,b) a=min(a,b)
int dh[4]={1,-1,0,0};
int dw[4]={0,0,1,-1};
int ddh[8]={-1,-1,-1,0,0,1,1,1};
int ddw[8]={-1,0,1,-1,1,-1,0,1};
ll gcd(ll a,ll b){
    if(a<b)swap(a,b);
    if(b==0)return a;
    if(a%b==0)return b;
    return gcd(b,a%b);
}
ll Pow(ll n,ll k){
    ll ret=1;
    ll now=n;
    while(k>0){
        if(k&1)ret*=now;
        now*=now;
        k/=2;
    }
    return ret;
}
ll beki(ll n,ll k,ll md){
  ll ret=1;
  ll now=n;
  while(k>0){
    if(k%2==1){
      ret*=now;
      ret%=md;
    }
    now*=now;
    now%=md;
    k/=2;
  }
  return ret;
}
ll gyaku(ll n,ll md){
  return beki(n,md-2,md);
}
ll popcount(ll n){
    ll ret=0;
    ll u=n;
    while(u>0){
        ret+=u%2;
        u/=2;
        
    }
    return ret;
}

int main(){
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int n,x,y;cin>>n>>x>>y;
    vector<int> v[n+1];
    vector<pii> w;
    rep(i,0,n){
        int c,W;cin>>c>>W;
        w.push_back({W,c});
        v[c].push_back(W);
    }
    sort(w.begin(),w.end());
    rep(i,1,n+1)sort(v[i].begin(),v[i].end());
    ll cnt[n+1];
    fill(cnt,cnt+n+1,0);
    cnt[w[0].second]++;
    int jou;
    rep(i,1,n){
        if(w[0].first+w[i].first<=y)cnt[w[i].second]++;
        else{
            jou=i;
            break;
        }
    }
    ll sum=0;
    if(x>=y){
        rep(i,1,n+1){
            if(cnt[i]==0)continue;
            ll yy=upper_bound(v[i].begin(),v[i].end(),x-v[i][0])-v[i].begin();
            Max(cnt[i],yy);
            (sum+=cnt[i])%=mod;
        }
    }
    else{
        bool used[n];
        fill(used,used+n,false);
        used[0]=true;
        rep(i,1,n){
            if(w[i].second!=w[0].second)continue;
            if(w[i].first+w[0].first<=x)used[i]=true;
            else break;
        }
        int r=0;
        while(r<n&&w[r].second==w[0].second)r++;
        if(r==n){
            cout<<1<<endl;
            return 0;
        }
        //cout<<r<<endl;
        if(r<jou){
            rep(i,0,n){
                if(w[i].second!=w[0].second)continue;
                if(w[i].first+w[r].first<=y)used[i]=true;
                else break;
            }
        }
        cnt[w[0].second]=0;
        rep(i,0,n){
            cnt[w[0].second]+=used[i];
        }
        //cout<<cnt[w[0].second]<<endl;
        rep(i,1,n+1){
            (sum+=cnt[i])%=mod;
        }
    }
    ll ans=1;
    ll kai[200010];
    kai[0]=1;
    rep(i,1,200010){
        kai[i]=kai[i-1]*i%mod;
    }
    ans=kai[sum];
    rep(i,1,n+1){
        if(cnt[i]==0)continue;
        ll t=kai[cnt[i]];
        t=gyaku(t,mod);
        (ans*=t)%=mod;
    }
    cout<<ans<<endl;
}






Measured memory_bytes: 14192