#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
using namespace std;
const int N = 1<<20;
vector<int> nei[N<<5], adj[N], Lst[N][21], vec;
int L[N], R[N], Num[N<<5], rMx[N<<1], Par[N][21], Mx[N][21], cur = N, Ans = 1;
void Col(int u, int c){
Num[u] = c;
for (int i : nei[u]){
if (!Num[i])
Col(i, 3 - c);
if (Num[i] != 3 - c)
Ans = 0;
}
}
void Add(int i, int j){
nei[i].push_back(j);
nei[j].push_back(i);
}
void dfs(int u, int p){
Par[u][0] = p, Mx[u][0] = R[u];
for (int i=0;i<20;i++){
Par[u][i+1] = Par[Par[u][i]][i];
Mx[u][i+1] = Mx[Par[u][i]][i];
}
for (int i : adj[u])
dfs(i, u);
}
int getMx(int l, int r, int ans = 0){
for (l += N - 1, r += N + 1; l + 1 < r; l /= 2, r /= 2){
if (!(l & 1))
ans = max(ans, rMx[l ^ 1]);
if (r & 1)
ans = max(ans, rMx[r ^ 1]);
}
return ans;
}
void solve(int n, int S = 0){
set<pair<int, int>> st;
for (int i=0;i<=n;i++)
vec.push_back(i);
sort(begin(vec), end(vec), [](int i, int j){return L[i] < L[j];});
for (int i : vec){
int l = L[i], r = R[i];
while (st.size() > 0 and (*begin(st)).first < l)
st.erase(begin(st));
auto u = st.upper_bound({r, r});
if (u != st.end())
adj[(*u).second].push_back(i);
st.insert({r, i});
}
dfs(0, 0);
st.clear();
for (int I : vec){
while (st.size() > 0 and (*begin(st)).first < L[I])
st.erase(begin(st));
if (st.size() > 0 and (*begin(st)).first < R[I]){
auto [k, x] = *prev(st.upper_bound({R[I], R[I]}));
if (getMx(L[I], R[x]) > R[I])
Ans = 0;
k = (*begin(st)).second;
for (int i=20; i+1; i--){
if (Mx[k][i] < R[I])
Lst[k][i].push_back(I), k = Par[k][i];
}
}
st.insert({R[I], I});
}
for (int j=20; j + 1;j--){
for (int i=1;i<=n;i++){
if (Lst[i][j].size() == 0)
continue;
int id = (!j ? i : ++cur);
for (int k : Lst[i][j])
Add(id, k);
if (j){
cur++;
Add(id, cur);
Lst[i][j-1].push_back(cur);
Lst[Par[i][j-1]][j-1].push_back(cur);
}
vector<int> ().swap(Lst[i][j]);
}
}
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(NULL);
int n;
cin>>n;
R[0] = n + n + 1;
for (int i=1;i<=n;i++){
cin>>L[i]>>R[i];
for (int j=L[i]+N; j; j /= 2)
rMx[j] = max(rMx[j], R[i]);
}
solve(n);
for (int i=1;i<=n;i++){
if (Num[i] == 0)
Ans = (Ans + Ans) % 1000000007, Col(i, 1);
}
cout<<Ans<<'\n';
}
