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#include <vector>
#include <iostream>
#include <sstream>
#include <math.h>
#include <sys/time.h>
#include <cstdlib>
#include <algorithm>
#include <cassert>
#include <cstring>
#include <fstream>
#include <set>
#include <map>
#include <iomanip>
#include <queue>

#define FOR(i,a,b)  for(__typeof(b) i=(a);i<(b);++i)
#define REP(i,a)    FOR(i,0,a)
#define FOREACH(x,c)   for(__typeof(c.begin()) x=c.begin();x != c.end(); x++)
#define ALL(c)      c.begin(),c.end()
#define CLEAR(c)    memset(c,0,sizeof(c))
#define SIZE(c) (int) ((c).size())

#define PB          push_back
#define MP          make_pair
#define X           first
#define Y           second

#define ULL         unsigned long long
#define LL          long long
#define LD          long double
#define II         pair<int, int>
#define DD         pair<double, double>
#define FF          pair<float,float>

#define VC	    vector
#define VI          VC<int>
#define VVI         VC<VI>
#define VVVI        VC<VVI>
#define VD          VC<double>
#define VS          VC<string>
#define VII         VC<II>
#define VDD         VC<DD>
#define VFF         VC<FF>
#define VVD         VC<VD>
#define VVVD        VC<VVD>
#define VULL         VC<ULL>

#define DB(a)       cerr << #a << ": " << a << endl;

using namespace std;

template<class T> void print(VC < T > v) {cerr << "[";if (SIZE(v) != 0) cerr << v[0]; FOR(i, 1, SIZE(v)) cerr << "," << v[i]; cerr << "]\n";}
template<class T> string i2s(T &x) { ostringstream o; o << x; return o.str(); }
VS split(string &s, char c = ' ') {VS all; int p = 0, np; while (np = s.find(c, p), np >= 0) {all.PB(s.substr(p, np - p)); p = np + 1;} if (p < SIZE(s)) all.PB(s.substr(p)); return all;}

#define MOD 1000000007

ULL mod_inv(ULL x, ULL M){
    int a = M-2;
    ULL p = x;
    ULL res = 1;
    while (a != 0){
        if (a%2 == 1)
            res = (res*p) % M;
        a /= 2;
        p = (p*p) % M;
    } 
    return res;
}

int main(int argc, char *argv[]){
    int N;
    cin >> N;
    VII shelves(N,MP(-1,-1));
    VVI next(N); 
    set<II> ends;
    REP(i,N)
        cin >> shelves[i].X >> shelves[i].Y;

    for(int i=N-1; i >= 0; i--){
        int l = shelves[i].X;
        int r = shelves[i].Y;
        auto it1 = ends.lower_bound(MP(l,0));
        auto it2 = ends.upper_bound(MP(r,0));
        set<int> nextSet;
        for (auto it = it1; it != it2; it++)
            nextSet.insert(it->Y);
        ends.erase(it1,it2);

        next[i] = VI(ALL(nextSet));

        ends.insert(MP(l,i));
        ends.insert(MP(r,i));
    }
    /*for(auto e : next){
        for(auto x : e) 
            cout << x << " ";
        cout << endl;
    }*/
    VI reach(N,0);
    VI q;
    ULL res = 0;

    REP(i,N){
        int qInd = 0;
        q.clear();
        reach[i] = 1;
        q.PB(i);
        while (qInd < SIZE(q)){
            int x = q[qInd];
            qInd++;
            for(auto y : next[x])
                if (!reach[y]){
                    reach[y] = 1;
                    q.PB(y);
                }
        }
        for(auto x : q) 
            reach[x] = 0;
        res = (res+mod_inv(SIZE(q),MOD))%MOD;
    }
    cout << res << endl;
    return 0;
}