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#include <bits/stdc++.h>
#define fi first
#define sc second
#define pb push_back
#define rep(i,p,k) for(int i=(p);i<(k);++i)
#define forn(i,p,k) for(int i=(p);i<=(k);++i)
#define forr(i,k,p) for(int i=(k)-1;i>=(p);--i)
#define each(a,b) for(auto&a:b)
#define all(v)  begin(v), end(v)
#define RET(smth)   return void(cout<<(smth)<<'\n');
#define sz(v) (int)v.size()
using namespace std;
using pii = pair<int,int>;
using ll = long long;
using Vi = vector<int>;
#ifdef DEBUG
#include "debug.h"
#else
#define debug(...) ;
#endif

const int bs = 1<<20;
int mx[bs<<1];

void update(int p, int k, int val) {
    for(p+=bs-1,k+=bs+1;p+1!=k;p/=2,k/=2) {
        if((p&1)==0) mx[p+1] = val;
        if((k&1)==1) mx[k-1] = val;
    }
}

int query(int ind) {
    int r = mx[ind+=bs];
    for(ind/=2;ind;ind/=2) {
        r = max(r,mx[ind]);
    }
    return r;
}

const int P = 1e9+7;

ll mul(ll a, ll b) {
    return a*b%P;
}

const int C = 1024;

int main() {
#ifndef DEBUG
    cin.tie(0) -> sync_with_stdio(0);
#endif
    int n; cin >> n;
    vector<ll> inv(n+1);
    inv[1] = 1;
    forn(i,2,n) inv[i] = mul(P/i,P-inv[P%i]);
    vector<vector<int>> W(n);
    forn(i,1,n) {
        int l,r; cin >> l >> r;
        int L = query(l);
        int R = query(r);
        update(l,r,i);
        if(L)   W[L-1].push_back(i-1);
        if(R)   W[R-1].push_back(i-1);
    }
    vector<bitset<C>> dp(n, 0);
    Vi cnt(n, 0);
    for(int b = 0; b < n; b += C) {
        forr(i,n,0) {
            dp[i] = 0;
            if(b <= i && i < b + C) dp[i][i-b] = 1;
            for(auto v : W[i]) dp[i] |= dp[v];
        }
        rep(i,0,n) cnt[i] += dp[i].count();
    }
    for(auto&v:cnt) v = inv[v];
    cout << accumulate(all(cnt),0LL) % P << '\n';
    return 0;
}