#ifdef LOCKAL
#define _GLIBCXX_DEBUG
#endif
#ifndef LOCKAL
#pragma GCC optimize("Ofast")
#pragma GCC target("sse3,sse4")
#endif
#include <bits/stdc++.h>
//#define TIMUS
//#define FILENAME "journey"
#ifndef TIMUS
#include <ext/rope>
#include <ext/pb_ds/assoc_container.hpp>
#endif // TIMUS
#define all(x) x.begin(), x.end()
#define F first
#define S second
#define pb push_back
#define pii pair<int, int>
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
const int INF = INT_MAX / 2;
const ll LINF = (ll)2e18 + 666, M = 1e9 + 7;
const ld EPS = 1e-7;
#ifndef M_PI
const ld M_PI = acos(-1);
#endif // M_PI
using namespace std;
#ifndef TIMUS
using namespace __gnu_cxx;
using namespace __gnu_pbds;
template<class K, class T>
using ordered_map = tree<K, T, less<K>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#endif
void run();
template<class T1, class T2>
inline bool mini(T1 &a, T2 b)
{
if (a > b)
{
a = b;
return 1;
}
return 0;
}
template<class T1, class T2>
inline bool maxi(T1 &a, T2 b)
{
if (a < b)
{
a = b;
return 1;
}
return 0;
}
int main()
{
#ifndef LOCKAL
#ifdef FILENAME
freopen(FILENAME".in", "r", stdin);
freopen(FILENAME".out", "w", stdout);
#endif // FILENAME
#endif
#ifndef TIMUS
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
#endif // TIMUS
srand(time(0));
auto start = clock();
run();
#ifdef LOCKAL
//cout << endl;
cout << "\ntime = " << (ld)(clock() - start) / CLOCKS_PER_SEC << "\n";
#endif
return 0;
}
#define DEBUG
#if defined DEBUG && defined LOCKAL
#define debugdo(x) x
#else
#define debugdo(x)
#endif
#define debug(x) debugdo(cout << x << endl)
#define debug2(x) debugdo(cout << x << " ")
// ---SOLUTION--- //
vector<vector<int>> g;
vector<char> use;
void dfs(int v, char c = 1)
{
use[v] = c;
for (auto x: g[v])
{
if (!use[x])
dfs(x, c ^ 3);
else if (use[x] == use[v])
{
cout << 0;
exit(0);
}
}
}
void run()
{
int n;
cin >> n;
vector<int> e(n * 2), ap(n), bp(n);
for (int i = 0; i < n; i++)
{
int a, b;
cin >> a >> b;
e[a - 1] = i + 1;
e[b - 1] = -i - 1;
ap[i] = a - 1;
bp[i] = b - 1;
}
g.resize(n);
use.resize(n);
for (int i = 0; i < n; i++)
{
for (int j = ap[i] + 1; j < bp[i]; j++)
{
//debug(i << " " << j << " " << e[j]);
if (e[j] > 0)
{
if (bp[e[j] - 1] > bp[i])
{
//debug(i + 1 << " " << e[j]);
g[i].pb(e[j] - 1);
g[e[j] - 1].pb(i);
}
}
}
}
ll ans = 1;
for (int i = 0; i < n; i++)
{
if (!use[i])
{
dfs(i);
ans <<= 1;
ans %= M;
}
}
cout << ans;
}
/*
*/
