Language: C++

#include <iostream>
#include <fstream>
#include <cassert>
#include <typeinfo>
#include <vector>
#include <stack>
#include <cmath>
#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <cstdio>
#include <queue>
#include <iomanip>
#include <cctype>
#include <random>
#define syosu(x) fixed<<setprecision(x)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> P;
typedef pair<double,double> pdd;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<char> vc;
typedef vector<vc> vvc;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<P> vp;
typedef vector<vp> vvp;
typedef vector<pll> vpll;
typedef pair<P,int> pip;
typedef vector<pip> vip;
const int inf=1<<29;
const ll INF=1ll<<60;
const double pi=acos(-1);
const double eps=1e-8;
const ll mod=1e9+7;
const int dx[4]={0,1,0,-1},dy[4]={1,0,-1,0};

const int M=2*100000+1;
const vi emp;

ll Pow_mod(ll n,ll p){
	ll r=1;
	for(;p>0;p>>=1){
		if(p&1) r=(r*n)%mod;
		n=(n*n)%mod;
	}
	return r;
}

ll Division_mod(ll n,ll m){
	return n*Pow_mod(m,mod-2)%mod;
}

vl fact(M);

void Init(){
	fact[0]=1;
	for(int i=1;i<M;i++) fact[i]=fact[i-1]*i%mod;
}

int n,x,y;
vvi a;

int main(){
	cin>>n>>x>>y;
	int cnt=0;
	map<int,int> m;
	for(int i=0;i<n;i++){
		int c,w;
		cin>>c>>w;
		if(m.find(c)==m.end()){
			m[c]=cnt;
			cnt++;
			a.push_back(emp);
		}
		a[m[c]].push_back(w);
	}
	int S=m.size();
	if(S==1){
		cout<<1<<endl;
		return 0;
	}
	for(int i=0;i<S;i++) sort(a[i].begin(),a[i].end());
	sort(a.begin(),a.end());
	vi b(S);
	for(int i=0;i<S;i++){
		auto it=upper_bound(a[i].begin(),a[i].end(),y-a[0][0]);
		if(it==a[i].begin()) break;
		b[i]=upper_bound(a[i].begin(),a[i].end(),x-a[i][0])-a[i].begin();
		if(i) b[i]=max(b[i],(int)(it-a[i].begin()));
		else b[i]=max(b[i],upper_bound(a[i].begin(),a[i].end(),y-a[1][0])-a[i].begin());
	}
//	for(int i=0;i<S;i++) cout<<b[i]<<' ';
//	cout<<endl;
	Init();
	ll res=1,sum=0;
	for(int i=0;i<S;i++){
		(res*=fact[b[i]])%=mod;
		sum+=b[i];
	}
	res=Division_mod(fact[sum],res);
	cout<<res<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:100:30: error: no matching function for call to 'max(__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type&, __gnu_cxx::__normal_iterator<int*, std::vector<int> >::difference_type)'
  100 |                 else b[i]=max(b[i],upper_bound(a[i].begin(),a[i].end(),y-a[1][0])-a[i].begin());
      |                           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/string:51,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:100:30: note:   deduced conflicting types for parameter 'const _Tp' ('int' and '__gnu_cxx::__normal_iterator<int*, std::vector<int> >::difference_type' {aka 'long int'})
  100 |                 else b[i]=max(b[i],upper_bound(a[i].begin(),a[i].end(),y-a[1][0])-a[i].begin());
      |                           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:11:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:100:30: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
  100 |                 else b[i]=max(b[i],upper_bound(a[i].begin(),a[i].end(),y-a[1][0])-a[i].begin());
      |                           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~