#include<bits/stdc++.h>
using namespace std;
#define task "a"
#define se second
#define fi first
#define ll long long
#define ii pair<ll, ll>
const long mxN = 2e6 + 7, MOD = 1e9 + 7;
ii lazy[mxN * 4], tree[mxN * 4], dsu[mxN], a[mxN];
int n;
void Down(int j)
{
if (!lazy[j].fi)
return;
if (tree[j * 2].fi)
{
tree[j * 2] = lazy[j];
lazy[j * 2] = lazy[j];
}
if (tree[j * 2 + 1].fi)
{
tree[j * 2 + 1] = lazy[j];
lazy[j * 2 + 1] = lazy[j];
}
lazy[j] = {0, 0};
}
void Up(int j)
{
if (!tree[j * 2].fi)
tree[j] = tree[j * 2 + 1];
else if (!tree[j * 2 + 1].fi)
tree[j] = tree[j * 2];
else if (tree[j * 2] != tree[j * 2 + 1])
tree[j].fi = -1;
else
tree[j] = tree[j * 2];
}
ii Find(int j)
{
if (dsu[j].fi != j)
{
ii res = Find(dsu[j].fi);
dsu[j].fi = res.fi;
dsu[j].se ^= res.se;
}
return dsu[j];
}
void Union(ii u, ii v)
{
bool tmp = u.se;
u = Find(u.fi);
if (u.fi == v.fi)
{
if ((u.se ^ tmp) == v.se)
{
cout << 0;
exit(0);
}
return;
}
dsu[u.fi].fi = v.fi;
dsu[u.fi].se ^= 1 ^ tmp;
return;
}
void Get(int u, int v, int id, int j = 1, int l = 1, int r = n * 2)
{
if (u > r || l > v || !tree[j].fi)
return;
if (u <= l && r <= v && tree[j].fi != -1)
{
Union(tree[j], {id, 0});
tree[j] = lazy[j] = {id, 1};
return;
}
Down(j);
int mid = (l + r) / 2;
Get(u, v, id, j * 2, l, mid);
Get(u, v, id, j * 2 + 1, mid + 1, r);
Up(j);
}
void Upd(int vt, int id, int j = 1, int l = 1, int r = n * 2)
{
if (vt > r || l > vt)
return;
if (l == r)
{
tree[j] = {id, 0};
return;
}
Down(j);
int mid = (l + r) / 2;
Upd(vt, id, j * 2, l, mid);
Upd(vt, id, j * 2 + 1, mid + 1, r);
Up(j);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
//freopen(task".INP", "r", stdin);
//freopen(task".OUT", "w", stdout);
cin >> n;
for (int i = 1; i <= n; i++)
{
cin >> a[i].fi >> a[i].se;
dsu[i].fi = i;
dsu[i].se = 0;
}
sort(a + 1, a + n + 1);
for (int i = 1; i <= n; i++)
{
Get(a[i].fi, a[i].se, i);
Upd(a[i].se, i);
}
ll ans = 1;
for (int i = 1; i <= n; i++)
{
if (Find(i).fi == i)
ans = ans * 2 % MOD;
}
cout << ans;
}
