#include <bits/stdc++.h>
using namespace std;
const int maxN = 1e6 + 5;
const int MOD = 1e9 + 7;
int n;
pair <int, int> a[maxN];
int vis[4 * maxN];
int lab[4 * maxN];
vector <int> g[4 * maxN];
int st_min[4 * maxN], st_max[4 * maxN];
int find (int x) {return lab[x] < 0 ? x : lab[x] = find(lab[x]);}
bool joint (int u, int v)
{
int x = find(u), y = find(v);
if (x == y) return false;
if (lab[x] > lab[y]) swap (x, y);
lab[x]+= lab[y];
lab[y] = x;
return 1;
}
void add (int u, int v)
{
joint (u, v + n);
joint (v, u + n);
if (find(u) == find(u + n))
{
cout << 0;
exit(0);
}
if (find(v) == find(v + n))
{
cout << 0;
exit(0);
}
}
void build (int id, int l, int r)
{
if (l == r)
{
st_min[id] = 1e9;
st_max[id] = 0;
return;
}
int mid = (l + r) >> 1;
build (id << 1, l, mid);
build (id << 1 | 1, mid + 1, r);
}
void up (int pos, int val)
{
int id = 1, l = 1, r = 2 * n;
while (l < r)
{
int mid = l + r >> 1;
if (pos <= mid) id = id << 1, r = mid;
else id = id << 1 | 1, l = mid + 1;
}
st_min[id] = st_max[id] = val;
while (id > 1)
{
id >>= 1;
st_max[id] = max(st_max[id << 1], st_max[id << 1 | 1]);
st_min[id] = min(st_min[id << 1], st_min[id << 1 | 1]);
}
}
void addEdge (int id, int l, int r, int u, int v, int pos)
{
if (l > v || r < u || st_max[id] == 0) return;
if (l >= u && r <= v)
{
if (st_max[id] == st_min[id])
{
add (pos, st_max[id]);
// cout << pos << " " << st_max[id] << "\n";
g[st_max[id]].push_back(pos);
return;
}
if (l == r)
{
// cout << pos << " " << st_max[id] << "\n";
g[st_max[id]].push_back(pos);
add (pos, st_max[id]);
return;
}
}
int mid = (l + r) >> 1;
addEdge (id << 1, l, mid, u, v, pos);
addEdge (id << 1 | 1, mid + 1, r, u, v, pos);
st_max[id] = max (st_max[id << 1], st_max[id << 1 | 1]);
st_min[id] = min (st_min[id << 1], st_min[id << 1 | 1]);
}
void dfs (int u)
{
vis[u] = 1;
for (int &v : g[u]) if (!vis[v]) dfs(v);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
cin >> n;
for (int i = 1; i <= n; i++) cin >> a[i].first >> a[i].second;
sort (a + 1, a + 1 + n);
memset(lab, - 1, sizeof lab);
build (1, 1, 2 * n);
for (int i = 1; i <= n; i++)
{
addEdge (1, 1, 2 * n, a[i].first, a[i].second, i);
up (a[i].second, i);
}
int ans = 1;
for (int i = 1; i <= n; i++)
{
if (!vis[i])
{
dfs(i);
ans = 1LL * 2 * ans % MOD;
}
}
cout << ans;
return 0;
}
