#include <bits/stdc++.h>
#define dbg() cerr <<
#define name(x) (#x) << ": " << (x) << ' ' <<
using namespace std;
const int MOD = (int)1e9 + 7;
template<class T, class F = function<T(const T&, const T&)>>
struct SegmTree {
int n;
T def;
F f;
vector<T> t;
SegmTree(int n_, T def_, F f_) : n(n_), def(def_), f(f_), t(4 * n, def) {}
void Update(int node, int left, int right, int pos, T val) {
if (pos < left || pos > right) return;
if (left == right) {
t[node] = val;
return;
}
int mid = left + (right - left) / 2;
Update(2 * node + 1, left, mid, pos, val);
Update(2 * node + 2, mid + 1, right, pos, val);
t[node] = f(t[2 * node + 1], t[2 * node + 2]);
}
T Query(int node, int left, int right, int x, int y) {
if (right < x || y < left) return def;
if (x <= left && right <= y) {
return t[node];
}
int mid = left + (right - left) / 2;
return f(Query(2 * node + 1, left, mid, x, y),
Query(2 * node + 2, mid + 1, right, x, y));
}
void Update(int pos, T val) {
Update(0, 0, n - 1, pos, val);
}
T Query(int l, int r) {
if (l > r) return def;
return Query(0, 0, n - 1, l, r);
}
};
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int n; cin >> n;
vector<pair<int, int>> v(n);
for (int i = 0; i < n; ++i) {
int x, y; cin >> x >> y; --x, --y;
v[i] = {x, y};
}
SegmTree<pair<int, int>> beg(2 * n, {2 * n, 2 * n},
[](pair<int, int> a, pair<int, int> b) {
return min(a, b);
});
SegmTree<pair<int, int>> fin(2 * n, {-1, -1},
[](pair<int, int> a, pair<int, int> b) {
return max(a, b);
});
for (int i = 0; i < n; ++i) {
fin.Update(v[i].first, {v[i].second, i});
beg.Update(v[i].second, {v[i].first, i});
}
vector<int> color(n, -1);
function<void(int, int)> DFS = [&](int node, int col) {
color[node] = col;
fin.Update(v[node].first, {-1, -1});
beg.Update(v[node].second, {2 * n, 2 * n});
while (true) {
auto p = fin.Query(v[node].first + 1, v[node].second - 1);
if (p.first < v[node].second) break;
DFS(p.second, 1 ^ col);
}
while (true) {
auto p = beg.Query(v[node].first + 1, v[node].second - 1);
if (p.first > v[node].first) break;
DFS(p.second, 1 ^ col);
}
};
int ans = 1;
for (int i = 0; i < n; ++i) {
if (color[i] == -1) {
ans += ans;
if (ans >= MOD) ans -= MOD;
DFS(i, 0);
}
}
vector<int> events(2 * n);
for (int i = 0; i < n; ++i) {
events[v[i].first] = i;
events[v[i].second] = ~i;
}
vector<vector<int>> stacks(2);
for (int node : events) {
auto &stk = stacks[color[node < 0 ? ~node : node]];
if (node >= 0) {
stk.emplace_back(node);
} else {
node = ~node;
if (!stk.empty() && stk.back() == node) stk.pop_back();
}
}
if (stacks[0].empty() && stacks[1].empty()) {
cout << ans << endl;
} else {
cout << 0 << endl;
}
}
