#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int MAXN = 1e6;
const ll MOD = 1e9+7;
struct Data
{
int L, R;
};
int N, col[MAXN+10];
Data A[MAXN+10];
vector<int> adj[MAXN+10];
vector<pii> tree1[MAXN*8+10], tree2[MAXN*8+10];
void update1(int node, int tl, int tr, int l, int r, int k)
{
tree1[node].push_back(pii(l, k));
sort(tree1[node].begin(), tree1[node].end(), greater<pii>());
if(tl==tr) return;
int mid=tl+tr>>1;
if(r<=mid) update1(node*2, tl, mid, l, r, k);
else update1(node*2+1, mid+1, tr, l, r, k);
}
void query1(int node, int tl, int tr, int l, int r, int k)
{
int i, j;
if(r<tl || tr<l) return;
if(l<=tl && tr<=r)
{
while(!tree1[node].empty() && tree1[node].back().first<l)
{
if(!col[tree1[node].back().second]) adj[k].push_back(tree1[node].back().second);
tree1[node].pop_back();
}
return;
}
int mid=tl+tr>>1;
query1(node*2, tl, mid, l, r, k);
query1(node*2+1, mid+1, tr, l, r, k);
}
void update2(int node, int tl, int tr, int l, int r, int k)
{
tree2[node].push_back(pii(r, k));
sort(tree2[node].begin(), tree2[node].end());
if(tl==tr) return;
int mid=tl+tr>>1;
if(l<=mid) update2(node*2, tl, mid, l, r, k);
else update2(node*2+1, mid+1, tr, l, r, k);
}
void query2(int node, int tl, int tr, int l, int r, int k)
{
int i, j;
if(r<tl || tr<l) return;
if(l<=tl && tr<=r)
{
while(!tree2[node].empty() && tree2[node].back().first>r)
{
if(!col[tree2[node].back().second]) adj[k].push_back(tree2[node].back().second);
tree2[node].pop_back();
}
return;
}
int mid=tl+tr>>1;
query2(node*2, tl, mid, l, r, k);
query2(node*2+1, mid+1, tr, l, r, k);
}
int main()
{
int i, j;
scanf("%d", &N);
for(i=1; i<=N; i++) scanf("%d%d", &A[i].L, &A[i].R);
for(i=1; i<=N; i++) update1(1, 1, 2*N, A[i].L, A[i].R, i);
for(i=1; i<=N; i++) update2(1, 1, 2*N, A[i].L, A[i].R, i);
int cnt=0;
for(i=1; i<=N; i++)
{
if(col[i]) continue;
queue<int> Q;
cnt++;
Q.push(i); col[i]=1;
while(!Q.empty())
{
int now=Q.front(); Q.pop();
query1(1, 1, 2*N, A[now].L, A[now].R, now);
query2(1, 1, 2*N, A[now].L, A[now].R, now);
for(auto nxt : adj[now])
{
if(col[nxt]) continue;
Q.push(nxt); col[nxt]=3-col[now];
}
}
}
vector<int> S[3];
vector<pii> todo;
for(i=1; i<=N; i++) todo.push_back({A[i].L, i}), todo.push_back({A[i].R, i+N});
sort(todo.begin(), todo.end());
for(auto it : todo)
{
if(it.second>N)
{
if(!S[1].empty() && S[1].back()==it.second-N) S[1].pop_back();
else if(!S[2].empty() && S[2].back()==it.second-N) S[2].pop_back();
else return !printf("0");
}
else
{
S[col[it.second]].push_back(it.second);
}
}
ll ans=1;
for(i=1; i<=cnt; i++) ans=ans*2%MOD;
printf("%lld", ans);
}
