#include "bits/stdc++.h"
using namespace std;
const int MAXN = 2e6 + 10;
const int MOD = 1e9 + 7;
#define int long long
mt19937_64 rng((int)std::chrono::steady_clock::now().time_since_epoch().count());
int rnd(int x, int y) {
int u = uniform_int_distribution<int>(x, y)(rng); return u;
}
long long bm(long long b, long long p) {
if(p==0) return 1;
long long r = bm(b, p/2);
if(p&1) return (((r*r) % MOD) * b) % MOD;
return (r*r) % MOD;
}
struct segment {
int l, r;
};
bool cmp(segment a, segment b) {
return a.l < b.l;
}
vector<int> adj[MAXN];
char c[MAXN];
bool vis[MAXN];
void dfs(int node, char cur) {
c[node] = cur, vis[node] = 1;
for(int x: adj[node]) {
if(!vis[x]) {
dfs(x, (cur == 'A' ? 'B' : 'A'));
}
}
}
int st[8 * MAXN];
void u(int l, int r, int tar, int idx, int val) {
if(l == r) {
st[idx] = val; return;
}
int mid = (l + r) >> 1;
if(tar <= mid) u(l, mid, tar, 2*idx+1, val);
else u(mid+1, r, tar, 2*idx+2, val);
st[idx] = max(st[2*idx+1], st[2*idx+2]);
}
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);
return max(qu(l, r, constl, mid, 2*idx+1), qu(l, r, mid+1, constr, 2*idx+2));
}
void update(int i, int v) {
u(0, 2*MAXN-1, i, 0, v);
}
int query(int l, int r) {
return qu(l, r, 0, 2*MAXN-1, 0);
}
void solve(int tc) {
int n;
cin >> n;
segment s[n+1];
for(int i=1; i<=n; i++)cin >> s[i].l >> s[i].r;
sort(s+1, s+n+1, cmp);
int oops[2*n + 1];
for(int i=1; i<=n; i++) oops[s[i].r] = i;
for(int i=1; i<=n; i++) update(s[i].l, s[i].r);
time_t t = clock();
for(int i=1; i<=n; i++) {
if(s[i].l + 1 == s[i].r) continue;
vector<pair<int, int> > v;
int mi = 0;
while(1) {
int res = query(s[i].l + 1, s[i].r - 1);
if(res > s[i].r) {
adj[i].push_back(oops[res]);
adj[oops[res]].push_back(i);
if(s[oops[res]].l < mi || (double)(clock() - t) * 1.0 / CLOCKS_PER_SEC > 5.60) {
cout << "0\n"; return;
}
mi = s[oops[res]].l;
v.push_back({s[oops[res]].l, res});
update(s[oops[res]].l, -1);
}
else {
break;
}
}
for(pair<int, int> x: v) {
update(x.first, x.second);
}
}
int compo = 0;
for(int i=1; i<=n; i++) {
if(!vis[i]) {
compo++;
dfs(i, 'A');
}
}
for(int i=1; i<=n; i++) {
for(int x: adj[i]) {
if(c[i] == c[x]) {
cout << "0\n"; return;
}
}
}
cout << bm(2, compo) << '\n';
}
int32_t main(){
ios::sync_with_stdio(0); cin.tie(0);
int t = 1; //cin >> t;
for(int i=1; i<=t; i++) solve(i);
}
/*
3 3
0 1 1 3
1 2 4 1
0 2 3 1
*/
