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#pragma GCC optimize ("Ofast")
#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define FOR(i, a, b) for (auto i=(a); i<(b); i++)
#define FORD(i, a, b) for (int i=(a); i>(b); i--)
#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(), (x).end()
#define PPC(x) __builtin_popcountll(x)
#define MSB(x) (63 - __builtin_clzll(x))
#define LSB(x) __builtin_ctzll(x)
#define ARG(x, i) (get<i>(x))
#define ithBit(m, i) ((m) >> (i) & 1)
#define pb push_back
#define ft first
#define sd second
#define kw(a) ((a) * (a))
#define CLR(x) x.clear(), x.shrink_to_fit()
#ifdef DEBUG
#include "debug.h"
#else
#define dbg(...) 0
#endif
using namespace std;
 
template <typename T1, typename T2> inline void remin(T1& a, T2 b) { a = min(a, (T1)b);	}
template <typename T1, typename T2> inline void remax(T1& a, T2 b) { a = max(a, (T1)b);	}

const int maxN = 1 << 19, maxTS = maxN * 4, mod = 1'000'000'007;

template <typename T1, typename T2> inline void addMod(T1& a, T2 b) { a = (a + b) % mod; }
template <typename T1, typename T2> inline void multMod(T1& a, T2 b) { a = a * b % mod; }

long long qpow(long long a, long long b)
{
	long long ret = 1ll;
	for (; b != 0; b /= 2)
	{
		if (b & 1)	multMod(ret, a);
		multMod(a, a);
	}
	return ret;
}

template <typename Tp> struct Tree_t
{
	int offset, qbegin, qend;
	Tp T[maxTS], x;
	
	void upriv(int v, int left, int right)
	{	
		if (left >= qend or right <= qbegin)
			return;
		if (left >= qbegin and right <= qend)
		{
			T[v] = x;
			return;
		}
		upriv(v * 2, left, (left + right) / 2);
		upriv(v*2+1, (left + right) / 2, right);
	}	
	
	void init(int n)
	{
		for (offset = 1; offset < n; offset *= 2) ;
	}
	
	void upd(int a, int b, int val)
	{
		qbegin = a + offset;
		qend = b + offset;
		x = val;
		upriv(1, offset, offset * 2);
	}

	int query(int v)
	{
		int ret = 0;
		for (v += offset; v != 0; v /= 2)
			remax(ret, T[v]);
		return ret;
	}
};
typedef Tree_t <int> Tree;

Tree tree;
int L[maxN], R[maxN], ancs[maxN], vis[maxN], visCtr;

void dfs(int v)
{
	vis[v] = visCtr;
	ancs[v]++;

	for (int u : { L[v], R[v] })
		if (u and vis[u] != visCtr)
			dfs(u);
}

void solve()
{
	int n;
	scanf ("%d", &n);
	
	tree.init(n*2+1);

	FOR(i, 1, n+1)
	{
		int a, b;
		scanf ("%d%d", &a, &b);
		L[i] = tree.query(a);
		R[i] = tree.query(b);
		tree.upd(a, b, i);
		visCtr++;
		dfs(i);
	}

	long long res = 0;
	FOR(i, 1, n+1)
		addMod(res, qpow(ancs[i], mod-2));		
	printf("%lld\n", res);
}

int main()
{
	int t = 1;
//	scanf ("%d", &t);	
	FOR(tid, 1, t+1)
	{
		//printf("Case #%d: ", tid);
		solve();
	}
	return 0;
}