#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)
template<typename T>
void amin(T &a, T b) {
a = min(a,b);
}
template<typename T>
void amax(T &a, T b) {
a = max(a,b);
}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
/*
*/
const int MOD = 1e9 + 7;
const int N = 1e6 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
template<typename T>
struct segtree1 {
// https://codeforces.com/blog/entry/18051
/*=======================================================*/
struct data {
ll mx,ind;
};
data neutral = {-inf2,-1};
data merge(data &left, data &right) {
data curr;
if(left.mx >= right.mx) curr = left;
else curr = right;
return curr;
}
void create(int i, T v) {
tr[i] = {v.ff,v.ss};
}
void modify(int i, T v) {
tr[i] = {v.ff,v.ss};
}
/*=======================================================*/
int n;
vector<data> tr;
segtree1() {
}
segtree1(int siz) {
init(siz);
}
void init(int siz) {
n = siz;
tr.assign(2 * n, neutral);
}
void build(vector<T> &a, int siz) {
rep(i, siz) create(i + n, a[i]);
rev(i, n - 1, 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
}
void pupd(int i, T v) {
modify(i + n, v);
for (i = (i + n) >> 1; i; i >>= 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
}
data query(int l, int r) {
data resl = neutral, resr = neutral;
for (l += n, r += n; l <= r; l >>= 1, r >>= 1) {
if (l & 1) resl = merge(resl, tr[l++]);
if (!(r & 1)) resr = merge(tr[r--], resr);
}
return merge(resl, resr);
}
};
template<typename T>
struct segtree2 {
// https://codeforces.com/blog/entry/18051
/*=======================================================*/
struct data {
ll mn,ind;
};
data neutral = {inf2,-1};
data merge(data &left, data &right) {
data curr;
if(left.mn <= right.mn) curr = left;
else curr = right;
return curr;
}
void create(int i, T v) {
tr[i] = {v.ff,v.ss};
}
void modify(int i, T v) {
tr[i] = {v.ff,v.ss};
}
/*=======================================================*/
int n;
vector<data> tr;
segtree2() {
}
segtree2(int siz) {
init(siz);
}
void init(int siz) {
n = siz;
tr.assign(2 * n, neutral);
}
void build(vector<T> &a, int siz) {
rep(i, siz) create(i + n, a[i]);
rev(i, n - 1, 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
}
void pupd(int i, T v) {
modify(i + n, v);
for (i = (i + n) >> 1; i; i >>= 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
}
data query(int l, int r) {
data resl = neutral, resr = neutral;
for (l += n, r += n; l <= r; l >>= 1, r >>= 1) {
if (l & 1) resl = merge(resl, tr[l++]);
if (!(r & 1)) resr = merge(tr[r--], resr);
}
return merge(resl, resr);
}
};
void solve(int test_case)
{
ll n; cin >> n;
vector<pll> a(n+5);
rep1(i,n) cin >> a[i].ff >> a[i].ss;
sort(a.begin()+1,a.begin()+n+1);
vector<pll> lx(2*n+5,{inf2,-1}), rx(2*n+5,{-inf2,-1});
rep1(i,n) lx[a[i].ss] = {a[i].ff,i};
rep1(i,n) rx[a[i].ff] = {a[i].ss,i};
segtree1<pll> st1(2*n+5);
segtree2<pll> st2(2*n+5);
st1.build(rx,2*n+1);
st2.build(lx,2*n+1);
vector<ll> vis(n+5);
vector<ll> col(n+5);
ll ans = 1;
rep1(i,n){
if(vis[i]) conts;
queue<ll> q;
q.push(i);
vis[i] = 1;
st1.pupd(a[i].ff,{-inf2,-1});
st2.pupd(a[i].ff,{inf2,-1});
while(!q.empty()){
ll u = q.front();
q.pop();
auto [l,r] = a[u];
while(true){
auto [mxr,v] = st1.query(l,r);
if(mxr < r) break;
if(!vis[v]){
q.push(v);
vis[v] = 1;
col[v] = col[u]^1;
}
st1.pupd(a[v].ff,{-inf2,-1});
}
while(true){
auto [mnl,v] = st2.query(l,r);
if(mnl > l) break;
if(!vis[v]){
q.push(v);
vis[v] = 1;
col[v] = col[u]^1;
}
st2.pupd(a[v].ss,{inf2,-1});
}
}
ans = ans*2%MOD;
}
rep(c,2){
stack<ll> stk;
rep1(i,2*n){
ll j = max(lx[i].ss,rx[i].ss);
if(col[j] != c) conts;
if(a[j].ff == i){
stk.push(j);
}
else{
if(stk.empty()){
ans = 0;
break;
}
if(stk.top() != j){
ans = 0;
}
stk.pop();
}
}
}
cout << ans << endl;
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
