#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6 + 100, mod = 1e9 + 7;
pair <int, int> a[maxn];
int u[maxn], x[2 * maxn];
struct Node
{
int L, R, mid;
pair <int, int> v;
Node *lc, *rc;
Node (int l, int r)
{
L = l, R = r, mid = (L + R) / 2, v = {0, 0}, lc = rc = NULL;
return ;
}
void init()
{
if (R - L == 1)
{
v = {a[L].second, L};
return ;
}
lc = new Node(L, mid);
rc = new Node(mid, R);
lc->init();
rc->init();
v = max(lc->v, rc->v);
return ;
}
void init2()
{
if (R - L == 1)
{
v = {x[L], x[L]};
return ;
}
lc = new Node(L, mid);
rc = new Node(mid, R);
lc->init2();
rc->init2();
v = max(lc->v, rc->v);
return ;
}
void update (int p, int val = 0)
{
if (R - L == 1)
{
v = {val, 0};
return ;
}
if (p < mid)
{
lc->update(p, val);
}
else
{
rc->update(p, val);
}
v = max(lc->v, rc->v);
return ;
}
pair <int, int> get(int l, int r)
{
if (l >= r)
{
return {-mod, -mod};
}
if (l == L and R == r)
{
return v;
}
pair <int, int> ret = {-mod, -mod};
if (l < mid)
{
ret = max(ret, lc->get(l, min(r, mid)));
}
if (r > mid)
{
ret = max(ret, rc->get(max(l, mid), r));
}
return ret;
}
};
Node *root[4];
bool mark[maxn][2];
void dfs(int v, bool s)
{
if (mark[v][s])
{
return ;
}
mark[v][s] = 1;
if (mark[v][s] and mark[v][s ^ 1])
{
cout << 0;
exit(0);
}
//cout << v << ' ' << s << endl;
while (true)
{
pair <int, int> tmp = root[s]->get(v + 1, u[v]);
if (tmp.first < a[v].second)
{
break;
}
root[s]->update(tmp.second);
//cout << v << "-->" << tmp.second << endl;
dfs(tmp.second, s ^ 1);
}
while (true)
{
int tmp = -root[2 + s]->get(a[v].first, a[v].second).first;
//cout << v << " founr " << tmp << endl;
if (tmp == 0 or tmp > v)
{
break;
}
root[2 + s]->update(a[tmp].second, -mod);
//cout << v << "-->" << tmp << endl;
dfs(tmp, s ^ 1);
}
return ;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n;
cin >> n;
for (int i = 1;i <= 2 * n;i++)
{
x[i] = -mod;
}
for (int i = 1;i <= n;i++)
{
cin >> a[i].first >> a[i].second;
}
sort(a + 1, a + 1 + n);
for (int i = 1;i <= n;i++)
{
u[i] = lower_bound(a + 1, a + 1 + n, make_pair(a[i].second, 0)) - a;
x[a[i].second] = -i;
}
root[0] = new Node(1, n + 1);
root[1] = new Node(1, n + 1);
root[0]->init();
root[1]->init();
root[2] = new Node(1, 2 * n + 1);
root[3] = new Node(1, 2 * n + 1);
root[2]->init2();
root[3]->init2();
int ans = 1;
for (int i = 1;i <= n;i++)
{
if (mark[i][0] or mark[i][1])
{
continue;
}
ans = ans * 2 % mod;
dfs(i, 0);
}
cout << ans;
return 0;
}
