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#include<bits/stdc++.h>
 
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("trapv")
 
#define st first
#define nd second
#define pb push_back
#define pp pop_back
#define eb emplace_back
#define mp(a, b) make_pair(a, b)
#define all(x) (x).begin(), (x).end()
#define rev(x) reverse(all(x))
#define sor(x) sort(all(x))
#define sz(x) (int)(x).size()
#define rsz(x) resize(x)
 
using namespace std;
 
///~~~~~~~~~~~~~~~~~~~~~~~~~~
 
template <typename H, typename T> 
ostream& operator<<(ostream& os, pair<H, T> m){
	return os <<"("<< m.st<<", "<<m.nd<<")";
}
template <typename H> 
ostream& operator<<(ostream& os, vector<H> V){
	os<<"{";
	for(int i=0; i<V.size(); i++){
		if(i)os<<" ";
		os<<V[i];
	}
	os<<"}";
	return os;
}
 
void debug(){cerr<<"\n";}
template <typename H, typename... T>
void debug(H h, T... t) {cerr<<h; if (sizeof...(t)) cerr << ", "; debug(t...);}
#define deb(x...) cerr<<#x<<" = ";debug(x);
 
///~~~~~~~~~~~~~~~~~~~~~~~~~
 
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<pii > vii;
typedef vector<ll> vl;
typedef vector<pll> vll;
typedef string str;
 
#define BOOST ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
 
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
 
const int N=1<<20, K=21, INF=1e9+5, mod=1e9+7;
struct modint{
	int n=0;
	modint(){}
	modint(ll x){
		n=x%mod;
		if(n<0)n+=mod;
	}
	operator int(){
		return n;
	}
	modint operator+(modint a){a.n = n+a.n; if(a.n>=mod)a.n-=mod;return a;}
	modint operator+=(modint a){return (*this)=(*this)+a;}
	modint operator-(modint a){a.n = n-a.n; if(a.n<0)a.n+=mod;return a;}
	modint operator-=(modint a){return (*this)=(*this)-a;}
	modint operator*(modint a){a.n = (n*1ll*a.n)%mod; return a;}
	modint operator*=(modint a){return (*this)=(*this)*a;}
	modint pot(const ll &m)const{
		modint a(1);
		if(m==0)return a;
		if(m==1)return (*this);
		a=(*this).pot(m/2);
		a*=a;
		return a*((*this).pot(m&1));
	}
	modint odw(){
		return (*this).pot(mod-2);
	}
	modint operator/(modint a){return (*this)*a.odw();}
	modint operator/=(modint a){return (*this)=(*this)/a;}
	bool operator==(modint a){return a.n==n;}
	friend ostream& operator<<(ostream& os, modint m) {
		return os << m.n; 
	}
};

int tab[N+N];
pii wsp[N];
int sum[N];
void prop(int v){
	if(!tab[v]||v>=N)return;
	int l=v+v, r=l+1;
	tab[l]=tab[v];
	tab[r]=tab[v];
	tab[v]=0;
}
int find(int v){
	v+=N;
	int ans=0;
	while(v){
		//deb(v);
		if(tab[v])ans=tab[v];
		v>>=1;
	}
	return ans;
}
void ustaw(int v, int L, int R, int l, int r, int c){
	//deb(v, L, R, l, r, c);
	if(l==L && r==R){
		//deb(v, c);
		tab[v]=c;
		return;
	}
	prop(v);
	int M=(L+R)>>1;
	if(l<=M)ustaw(v+v, L, M, l, min(r, M), c);
	if(r>M) ustaw(v+v+1, M+1, R, max(l, M+1), r, c);
}
int L[K][N], R[K][N];

int main(){
	BOOST;
	int n;
	cin>>n;
	vii V(n);
	wsp[0]={0, 2*n+1};
	for(int i=1; i<=n; i++){
		cin>>wsp[i].st>>wsp[i].nd;
		L[0][i]=R[0][i]=i;
		L[1][i]=find(wsp[i].st);
		R[1][i]=find(wsp[i].nd);
		ustaw(1, 0, N-1, wsp[i].st, wsp[i].nd, i);
	}
	for(int k=2; k<K; k++){
		for(int i=1; i<=n; i++){
			L[k][i]=L[k-1][L[k-1][i]];
			R[k][i]=R[k-1][R[k-1][i]];
		}
	}
	for(int i=n; i>0; i--){
		sum[i]++;
		int l=L[1][i], r=R[1][i];
		sum[l]+=sum[i];
		sum[r]+=sum[i];
		int wskl=K-1, wskr=K-1;
		//deb(i, L[1][i], R[1][i], sum[i]);
		//deb(l, r);
		while(wskl||wskr){
			//deb(l, wskl, r, wskr);
			if(wskl && R[wskl][l]>=r){
				l=R[wskl--][l];
				continue;
			}
			if(wskr && L[wskr][r]>=l){
				r=L[wskr--][r];
				continue;
			}
			if(wsp[R[wskl][l]].nd>=wsp[L[wskr][r]].st){
				//deb("a");
				if(wskr && (!wskl || R[wskl][l]>L[wskr][r]))wskr--;
				else wskl--;
			}
			else{
				//deb("b");
				if(wskr && (!wskl || R[wskl][l]<L[wskr][r]))r=L[wskr--][r];
				else l=R[wskl--][l];
			}
		}
		//deb(l, r, R[1][l], L[1][r], wsp[R[1][l]].nd, wsp[L[1][r]].st);
		//deb(wsp[l], wsp[r]);
		if(l>r){
			for(int k=K-1; k>0;k--){
				if(R[k][l]>r)l=R[k][l];
			}
			l=R[1][l];
			for(int k=K-1; k>0;k--){
				if(L[k][r]>l)r=L[k][r];
			}
			if(L[1][r]>=l)r=L[1][r];
		}
		if(r>l){
			for(int k=K-1; k>0;k--){
				if(L[k][r]>l)r=L[k][r];
			}
			r=L[1][r];
			for(int k=K-1; k>0;k--){
				if(R[k][l]>r)l=R[k][l];
			}
			if(R[1][l]>=r)l=R[1][l];
		}
		//deb(l, r, R[1][l], L[1][r]);
		//if(l>r)l=R[1][l];
		//if(r>l)r=L[1][r];
		//if(l>r)l=R[1][l];
		/*deb(l, r, R[1][l], L[1][r]);
		deb(wsp[l], wsp[r]);
		int ll=L[1][i], rr=R[1][i];
		while(ll!=rr){
			if(ll>rr)ll=R[1][ll];
			else rr=L[1][rr];
		}
		deb(ll);
		assert(l==r);
		/*while(l!=r){
			if(l>r)l=R[1][l];
			else r=L[1][r];
		}*/
		sum[l]-=sum[i];
	}
	modint ans(0);
	for(int i=1; i<=n; i++){
		ans+=modint(1)/modint(sum[i]);
	}
	cout<<ans;
}