#include <bits/stdc++.h>
using namespace std;
using idata = vector<int>;
using num = long long;
const int START = 0;
const int END = 1;
const num MOD = 1e9 + 7;
struct Event {
int start, end;
Event () = default;
Event (int start, int end) : start(start), end(end) {}
};
struct Time {
int time, id;
int type;
Time (int time, int id, int type) : time(time), id(id), type(type) {}
bool operator< (const Time &other) {
return time < other.time;
}
};
struct UFD {
idata parents;
UFD (int size) {
parents.resize(size);
iota(parents.begin(), parents.end(), 0);
}
int boss (int x) {
if (parents[x] != x)
parents[x] = boss(parents[x]);
return parents[x];
}
bool merge (int a, int b) {
a = boss(a); b = boss(b);
if (a == b) return false;
parents[a] = b;
return true;
}
int size () {
int res = 0;
for (int i = 0; i < parents.size(); i ++)
if (i == parents[i])
res ++;
return res;
}
};
using vEvent = vector<Event>;
using vTime = vector<Time>;
vEvent events;
vTime timings;
const int MAXLOG = 23;
num pow2 (int k) {
num table[MAXLOG];
table[0] = 2;
for (int i = 1; i < MAXLOG; i ++) table[i] = (table[i - 1] * table[i - 1]) % MOD;
num res = 1;
for (int i = 0; i < MAXLOG; i ++)
if ((1 << i) & k)
res = (res * table[i]) % MOD;
return res;
}
int main () {
ios_base::sync_with_stdio(false); cin.tie(NULL);
int N; cin >> N;
events.resize(N);
for (int i = 0; i < N; i ++) {
int s, e;
cin >> s >> e;
events[i] = Event(s, e);
timings.push_back( Time(s, i, START) );
timings.push_back( Time(e, i, END ) );
}
sort(timings.begin(), timings.end());
reverse(timings.begin(), timings.end());
UFD ufd(N);
set<pair<int, int>> start_enabled;
for (Time &time : timings) {
int id = time.id;
bool isStart = time.type == START;
pair<int, int> start_pair = { events[id].start, id };
if (isStart) {
if (start_enabled.find(start_pair) != start_enabled.end())
start_enabled.erase(start_pair);
} else {
pair<int, int> search_pair = { events[id].start, -1 };
auto it = start_enabled.upper_bound(search_pair);
bool first = true;
while (it != start_enabled.end()) {
const auto data = *it;
int dataId = data.second;
if (!ufd.merge( id, dataId )) {
cout << "0\n";
return 0;
}
if (first) {
search_pair = data;
first = false;
} else start_enabled.erase(data);
it = start_enabled.upper_bound(search_pair);
}
start_enabled.insert(start_pair);
}
}
cout << pow2(ufd.size()) << endl;
}
