#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pii pair<int, int>
const int maxn = 1000010;
int mod = 1000000007;
int N;
ll ans, inv2;
vector<pii> vals;
set<int> cv; //current ending values
int seg[maxn*8]; //store max incoming in this range
int query(int qs, int qe, int ss = 1, int se = 2*N, int si = 0) {
if (qs > qe || ss > se || qs > se || qe < ss) return 0;
if (qs <= ss && se <= qe) return seg[si];
int mid = (ss+se)/2;
return max(query(qs, qe, ss, mid, si*2+1),
query(qs, qe, mid+1, se, si*2+2));
}
void update(int spot, int val, int ss = 1, int se = 2*N, int si = 0) {
if (ss == se) {
seg[si] = val;
return;
}
int mid = (ss+se)/2;
if (spot <= mid) {
update(spot, val, ss, mid, si*2+1);
}
else update(spot, val, mid+1, se, si*2+2);
seg[si] = max(seg[si*2+1], seg[si*2+2]);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> N;
ans = 1LL; //good start?
inv2 = (mod+1)/2LL;
int a, b;
for (int i = 0; i < N; i++) {
cin >> a >> b;
vals.push_back(pii(a, b));
update(a, b);
}
sort(vals.begin(), vals.end());
int pb = -1;
for (pii vp : vals) {
a = vp.first;
b = vp.second;
if (pb != -1) cv.insert(pb);
pb = b;
while (cv.size() && *(cv.begin()) < a) {
// cout << " thing: " << *(cv.begin()) << endl;
cv.erase(cv.begin());
}
if (cv.size() == 0) {
// cout << " option 1 " << endl;
ans = (ans*2)%mod;
continue;
}
auto it = cv.lower_bound(b);
if (it == cv.begin()) {
int cur = *it;
if (query(a+1, b) > cur) {
// cout << " option 3 " << endl;
continue;
}
// cout << " option 2" << endl;
ans = (ans*2LL)%mod;
}
else {
--it;
int cur = *it;
if (query(a+1, cur) > b) {
// cout << " option 4 " << endl;
ans = 0;
}
// cout << " option 5" << endl;
}
}
cout << ans << endl;
}
