#include "bits/stdc++.h"
#define int long long
using namespace std;
#ifdef ONLINE_JUDGE
const int MAXN = 1e6 + 10;
#endif
#ifndef ONLINE_JUDGE
const int MAXN = 73;
#endif
const int MOD = 1e9 + 7;
pair<int,int> p[MAXN];
int n;
stack<int> stka, stkb;
set<int> fin;
int dsu[MAXN];
int set_of(int u) {
if(dsu[u] == u) return u;
return dsu[u] = set_of(dsu[u]);
}
void union_(int u, int v) {
dsu[set_of(u)] = set_of(v);
}
int trigger[2*MAXN];
struct segtree_min {
vector<pair<int, int> > st;
int stok;
void u(int l, int r, int tar, int idx, int val1, int val2) {
if(l == r) {
st[idx] = {val1, val2};
return;
}
int mid = (l + r) >> 1;
if(tar <= mid) u(l, mid, tar, 2*idx+1, val1, val2);
else u(mid+1, r, tar, 2*idx+2, val1, val2);
st[idx] = min(st[2*idx+1], st[2*idx+2]);
}
pair<int,int> qu(int l, int r, int constl, int constr, int idx) {
if(l <= constl && constr <= r) return st[idx];
int mid = (constl+constr) >> 1;
if(mid<l || r <constl) return qu(l, r, mid+1, constr, 2*idx+2);
else if(constr<l || r<mid+1) return qu(l, r, constl, mid, 2*idx+1);
else {
return min(qu(l, r, constl, mid, 2*idx+1), qu(l, r, mid+1, constr, 2*idx+2));
}
}
void resize(int k) {
stok = k;
st.resize(4*k + 10);
}
void upd(int i, int v1, int v2) {
u(1, stok, i, 0, v1, v2);
}
pair<int,int> range_min(int l, int r) {
return qu(l, r, 1, stok, 0);
}
};
vector<int > adj[MAXN];
char c[MAXN];
bool vis[MAXN];
void dfs(int node) {
vis[node] = 1;
for(int x: adj[node]) {
if(!vis[x]) {
c[x] = (c[node] == 'A' ? 'B' : 'A');
dfs(x);
}
}
}
int32_t main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n;
for(int i=1; i<=n; i++) {
cin >> p[i].first >> p[i].second;
}
sort(p+1, p+1+n);
for(int i=1; i<=n; i++) dsu[i] = i;
for(int i=1; i<=n; i++) trigger[p[i].second] = i;
segtree_min stm;
stm.resize(2*n);
for(int i=1; i<=2*n; i++) stm.upd(i, 1e9, 0);
for(int i=1; i<=2*n; i++) {
if(trigger[i]) {
int l = p[trigger[i]].first, r = p[trigger[i]].second; // query [l, r]
pair<int,int> res = stm.range_min(l, r);
if(res.second != 0 && res.first < l) {
union_(res.second, trigger[i]);
adj[res.second].push_back(trigger[i]);
adj[trigger[i]].push_back(res.second);
}
stm.upd(i, l, trigger[i]);
}
}
for(int i=1; i<=2*n; i++) trigger[i] = 0;
for(int i=1; i<=n; i++) trigger[p[i].first] = i;
for(int i=1; i<=2*n; i++) stm.upd(i, 1e9, 0);
for(int i=2*n; i>=1; i--) {
if(trigger[i]) {
int l = p[trigger[i]].first, r = p[trigger[i]].second; // query [l, r]
pair<int,int> res = stm.range_min(l, r);
if(res.second != 0 && res.first < -r) {
union_(res.second, trigger[i]);
adj[res.second].push_back(trigger[i]);
adj[trigger[i]].push_back(res.second);
}
stm.upd(i, -r, trigger[i]);
}
}
for(int i=1; i<=n; i++) {
if(!vis[i]) {
c[i] = 'A';
dfs(i);
}
}
for(int i=1; i<=n; i++) {
while(stka.size() && stka.top() < p[i].first) stka.pop();
while(stkb.size() && stkb.top() < p[i].first) stkb.pop();
int alim = (stka.size() ? stka.top() : 1e9);
int blim = (stkb.size() ? stkb.top() : 1e9);
if(c[i] == 'A') {
if(alim < p[i].second) return cout << "0\n", 0;
stka.push(p[i].second);
}
else {
if(blim < p[i].second) return cout << "0\n", 0;
stkb.push(p[i].second);
}
}
int ans = 1;
for(int i=1; i<=n; i++) fin.insert(set_of(i));
int len = fin.size();
for(int i=0; i<len; i++) ans = (ans*2) % MOD;
cout << ans << "\n";
}
/*
6
2 8
6 12
1 9
4 7
10 11
3 5
7
8 12
2 10
5 7
11 14
1 3
4 13
6 9
*/
