#include <bits/stdc++.h>
using namespace std;
const long long mod=1e9+7;
long long p[8000005], r[8000005], a[8000005], b[8000005], id[8000005], id2[8000005], sz[8000005], pos[8000005];
vector<long long> st[8000005], adj[8000005];
bool sortt(long long x, long long y) {return a[x]<a[y];}
void makeset(long long x)
{
p[x]=x;
r[x]=0;
}
long long findset(long long x)
{
if (p[x]!=x) {p[x]=findset(p[x]);};
return p[x];
}
void unionsets(long long x, long long y)
{
x=findset(x);
y=findset(y);
if (x!=y)
{
if (r[x]<r[y]) {swap(x, y);};
p[y]=x;
if (r[x]==r[y]) {r[x]++;};
};
}
void build(long long x, long long l, long long r)
{
if (l>r) {return;}
else if (l==r)
{
if (pos[l]) {st[x].push_back(pos[l]);};
id2[x]=0; sz[x]=st[x].size();
}
else
{
build(x*2, l, (l+r)/2);
build(x*2+1, (l+r)/2+1, r);
long long i=0, j=0, sz1=st[x*2].size(), sz2=st[x*2+1].size();
while (i<sz1 || j<sz2)
{
if (i==sz1) {st[x].push_back(st[x*2+1][j]); j++;}
else if (j==sz2) {st[x].push_back(st[x*2][i]); i++;}
else if (a[st[x*2][i]]<a[st[x*2+1][j]]) {st[x].push_back(st[x*2][i]); i++;}
else {st[x].push_back(st[x*2+1][j]); j++;};
};
id2[x]=0; sz[x]=st[x].size();
};
}
void update(long long x, long long l, long long r, long long pos1, long long pos2)
{
if (l>r || l>pos2 || r<pos1 || pos1>pos2) {return;}
else if (pos1<=l && r<=pos2)
{
if (!st[x].empty() && a[st[x][0]]<pos1) {adj[pos[pos2+1]].push_back(st[x][0]);};
while (id2[x]<sz[x] && a[st[x][id2[x]]]<pos1)
{
if (id2[x]>0) {unionsets(st[x][id2[x]-1], st[x][id2[x]]);};
id2[x]++;
};
}
else
{
update(x*2, l, (l+r)/2, pos1, pos2);
update(x*2+1, (l+r)/2+1, r, pos1, pos2);
};
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
long long n, i, check=1, ans=1;
cin >> n;
for (i=1; i<=n; i++)
{
cin >> a[i] >> b[i];
id[i]=pos[b[i]]=i;
makeset(i);
};
sort(id+1, id+n+1, sortt);
build(1, 1, 2*n);
for (i=1; i<=n; i++)
{
update(1, 1, 2*n, a[id[i]]+1, b[id[i]]-1);
};
for (i=1; i<=n; i++)
{
for (auto x: adj[i])
{
if (findset(i)==findset(x)) {check=0;};
};
};
if (check==0) {cout << 0;}
else
{
for (i=1; i<=n; i++)
{
for (auto x: adj[i]) {unionsets(i, x);};
};
for (i=1; i<=n; i++)
{
if (findset(i)==i) {ans*=2; ans%=mod;};
};
cout << ans;
};
}
