// Author: caption_mingle
#include "bits/stdc++.h"
using namespace std;
#define ln "\n"
#define pb push_back
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define ll long long
const int mod = 1e9 + 7;
const int inf = 2e9;
const int N = 1e6 + 7;
int n, d[N], typ[N];
pair<int, int> a[N];
struct SEGTREE {
vector<int> st;
int n;
SEGTREE() {}
SEGTREE(int n) : n(n) {
st.resize(n * 4 + 4, -inf);
}
void update(int i, int l, int r, int u, int x) {
if(l > u or r < u) return;
if(l == r) {
st[i] = x;
return;
}
int m = (l + r) >> 1;
update(i * 2, l, m, u, x);
update(i * 2 + 1, m + 1, r, u, x);
st[i] = max(st[i * 2], st[i * 2 + 1]);
}
int get(int i, int l, int r, int u, int v) {
if(l > v or r < u) return -inf;
if(u <= l and r <= v) return st[i];
int m = (l + r) >> 1;
return max(get(i * 2, l, m, u, v), get(i * 2 + 1, m + 1, r, u, v));
}
void update(int u, int x) {
update(1, 1, n, u, x);
}
int get(int l, int r) {
return get(1, 1, n, l, r);
}
} lef, rig;
void dfs(int u) {
int c = typ[u];
// cerr << u << ln;
while(1) {
int x = rig.get(a[u].fi + 1, a[u].se - 1);
if(x < a[u].se) break;
// cerr << x << ' ' << a[u].se << ln;
int v = d[x];
typ[v] = c ^ 1;
rig.update(a[v].fi, -inf);
lef.update(a[v].se, -inf);
dfs(v);
}
while(1) {
int x = -lef.get(a[u].fi + 1, a[u].se - 1);
if(x > a[u].fi) break;
// cerr << x << ' ' << a[u].fi << ln;
int v = d[x];
typ[v] = c ^ 1;
rig.update(a[v].fi, -inf);
lef.update(a[v].se, -inf);
dfs(v);
}
}
vector<pair<int, int>> vec[2];
signed main() {
cin.tie(0) -> sync_with_stdio(0);
#define task ""
if(fopen(task ".INP", "r")) {
freopen(task ".INP", "r", stdin);
freopen(task ".OUT", "w", stdout);
}
cin >> n;
lef = rig = SEGTREE(n * 2);
for(int i = 1; i <= n; i++) {
cin >> a[i].fi >> a[i].se;
d[a[i].fi] = i;
d[a[i].se] = i;
lef.update(a[i].se, -a[i].fi);
rig.update(a[i].fi, a[i].se);
}
memset(typ, -1, sizeof typ);
int ans = 1;
for(int i = 1; i <= n; i++) {
if(typ[i] == -1) {
typ[i] = 0;
rig.update(a[i].fi, -inf);
lef.update(a[i].se, -inf);
dfs(i);
ans += ans;
if(ans >= mod) ans -= mod;
}
}
for(int i = 1; i <= n; i++) {
vec[typ[i]].pb({a[i].fi, i});
vec[typ[i]].pb({a[i].se, -i});
}
for(int i = 0; i < 2; i++) {
sort(all(vec[i]));
vector<int> st;
for(auto [x, id] : vec[i]) {
if(id > 0) st.pb(id);
else {
if(sz(st) == 0 or st.back() + id != 0) {
cout << 0;
return 0;
}
st.pop_back();
}
}
}
cout << ans << ln;
cerr << "\nTime: " << clock() * 1000 / CLOCKS_PER_SEC;
}
