#include<bits/stdc++.h>
#define god dimasi5eks
#pragma GCC optimize("O3")
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define mod 1000000007
#define dancila 3.14159265359
#define eps 1e-9
// #define fisier 1
using namespace std;
typedef long long ll;
int n;
pair<int, int> bk[1000002];
void chk()
{
vector<int> d[2];
for(int i = 1; i <= n; ++i)
{
for(int j = 0; j <= 1; ++j)
while(!d[j].empty() && d[j].back() < bk[i].fi)
d[j].pop_back();
if(d[0].empty() && d[1].empty())
d[0].pb(bk[i].se);
else
if(d[1].empty())
{
if(bk[i].se < d[0].back())
d[0].pb(bk[i].se);
else
d[1].pb(bk[i].se);
}
else
if(d[0].empty())
{
if(bk[i].se < d[1].back())
d[1].pb(bk[i].se);
else
d[0].pb(bk[i].se);
}
else
{
if(bk[i].se > max((int) d[0].back(), (int) d[1].back()))
{
cout << 0 << '\n';
exit(0);
}
if(d[0].back() < d[1].back())
{
if(bk[i].se < d[0].back())
d[0].pb(bk[i].se);
else
d[1].pb(bk[i].se);
}
else
{
if(bk[i].se < d[1].back())
d[1].pb(bk[i].se);
else
d[0].pb(bk[i].se);
}
}
}
}
int aint[4000002];
void build(int nod, int st, int dr)
{
if(st == dr)
{
aint[nod] = st;
return;
}
int mid = (st + dr) / 2;
build(nod << 1, st, mid);
build(nod << 1|1, mid+1, dr);
if(bk[aint[nod << 1]].se > bk[aint[nod << 1|1]].se)
aint[nod] = aint[nod << 1];
else
aint[nod] = aint[nod << 1|1];
}
void upd(int nod, int st, int dr, int poz)
{
if(st == dr)
{
aint[nod] = 0;
return;
}
int mid = (st + dr) / 2;
if(poz <= mid)
upd(nod << 1, st, mid, poz);
else
upd(nod << 1|1, mid+1, dr, poz);
if(bk[aint[nod << 1]].se > bk[aint[nod << 1|1]].se)
aint[nod] = aint[nod << 1];
else
aint[nod] = aint[nod << 1|1];
}
int query(int nod, int st, int dr, int L, int R)
{
if(dr < L || st > R)
return 0;
if(L <= st && dr <= R)
return aint[nod];
int mid = (st + dr) / 2;
int ans1 = query(nod << 1, st, mid, L, R);
int ans2 = query(nod << 1|1, mid+1, dr, L, R);
if(bk[ans1].se > bk[ans2].se)
return ans1;
else
return ans2;
}
bool viz[1000002];
int cb(int x)
{
int st = 1;
int dr = n;
int ans = 0;
while(st <= dr)
{
int mid = (st + dr) / 2;
if(bk[mid].fi <= x)
ans = mid, st = mid + 1;
else
dr = mid - 1;
}
return ans;
}
void dfs(int nod)
{
viz[nod] = 1;
upd(1, 1, n, nod);
while(1)
{
int poz = 0;
if(nod != 1)
poz = query(1, 1, n, 1, nod-1);
if(bk[poz].se > bk[nod].fi)
dfs(poz);
else
break;
}
while(1)
{
int poz = 0;
if(cb(bk[nod].se) > nod)
poz = query(1, 1, n, nod+1, cb(bk[nod].se));
else
poz = 0;
if(bk[poz].se > bk[nod].se)
dfs(poz);
else
break;
}
}
int main()
{
#ifdef fisier
ifstream f("input.in");
ofstream g("output.out");
#endif
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n;
for(int i = 1; i <= n; ++i)
cin >> bk[i].fi >> bk[i].se;
sort(bk + 1, bk + n + 1);
chk();
build(1, 1, n);
int ans = 1;
for(int i = 1; i <= n; ++i)
if(!viz[i])
{
ans = (ans * 2) % mod;
dfs(i);
}
cout << ans << '\n';
return 0;
}
