#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
#pragma warning (disable: 4996)
// 定数
const int MAX_N = (1 << 20);
const int MAX_BLOCK = 22;
// 一般
bool flag = false;
int N, L[MAX_N + 9], R[MAX_N + 9];
// グラフ
int cnts;
int col[MAX_N * MAX_BLOCK + 9], KAISOU;
int m_front[MAX_N * MAX_BLOCK + 9], m_back[MAX_N * MAX_BLOCK + 9];
vector<int> G[MAX_N * MAX_BLOCK + 9];
// セグ木
int SIZE_;
int el[MAX_N * 4 + 9], cnt[MAX_N * 4 + 9], cnt2[MAX_N * 4 + 9], C[MAX_N * 4 + 9];
pair<int, int> dat[MAX_N * MAX_BLOCK + 9];
// キュー
queue<int>Q;
void init() {
SIZE_ = 1; KAISOU = 1;
while (SIZE_ <= N * 2) { SIZE_ *= 2; KAISOU++; }
for (int i = 1; i <= N; i++) {
int cx = L[i] + SIZE_;
while (cx >= 1) {
cnt[cx]++; cx >>= 1;
}
}
for (int i = 0; i < SIZE_ * 2; i++) {
el[i + 1] = el[i] + cnt[i];
cnt2[i] = el[i];
}
}
void precount() {
for (int i = 1; i < SIZE_ * 2; i++) sort(dat + el[i], dat + el[i + 1]);
for (int i = 1; i < SIZE_ * 2; i++) C[i] = (1 << 30);
}
void query_(int l, int r, int x, int pos, int a, int b, int u) {
if (l <= a && b <= r) {
int pos1 = lower_bound(dat + el[u], dat + el[u + 1], make_pair(x, 0)) - dat;
if (pos1 < el[u + 1]) {
int id = dat[pos1].second;
G[pos].push_back(id);
G[id].push_back(pos);
}
C[u] = min(C[u], x);
return;
}
if (r <= a || b <= l) return;
query_(l, r, x, pos, a, (a + b) >> 1, u * 2);
query_(l, r, x, pos, (a + b) >> 1, b, u * 2 + 1);
}
void query(int cl, int cr, int x, int pos) {
query_(cl, cr, x, pos, 0, SIZE_, 1);
}
void lastcount() {
for (int i = 1; i < SIZE_ * 2; i++) {
for (int j = el[i]; j < el[i + 1] - 1; j++) {
if (C[i] <= dat[j].first) {
int id1 = dat[j].second;
int id2 = dat[j + 1].second;
m_back[id1] = id2;
m_front[id2] = id1;
}
}
}
}
int main() {
//FILE *in = freopen("in1.txt", "r", stdin);
scanf("%d", &N); vector<pair<int, int>> vec1;
for (int i = 1; i <= N; i++) {
scanf("%d%d", &L[i], &R[i]);
//L[i] = i; R[i] = i + N;
vec1.push_back(make_pair(L[i], R[i]));
}
sort(vec1.begin(), vec1.end());
for (int i = 1; i <= N; i++) { L[i] = vec1[i - 1].first; R[i] = vec1[i - 1].second; }
init();
for (int i = 1; i <= N; i++) {
int cl = SIZE_ + L[i];
dat[cnt2[cl]].first = R[i];
dat[cnt2[cl]].second = cnts;
cnt2[cl]++; cnts++;
while (cl >= 2) {
cl >>= 1;
dat[cnt2[cl]].first = R[i];
dat[cnt2[cl]].second = cnts;
cnt2[cl]++;
cnts++;
}
}
precount();
for (int i = 1; i <= N; i++) {
int pos1 = lower_bound(dat + el[1], dat + el[2], make_pair(R[i], 0)) - dat;
int id = dat[pos1].second;
query(L[i], R[i] + 1, R[i] + 1, id);
}
for (int i = 0; i <= cnts; i++) { m_back[i] = -1; m_front[i] = -1; }
lastcount();
for (int i = 0; i <= cnts; i++) col[i] = -1;
int components = 0;
for (int i = 0; i < cnts; i++) {
if (col[i] != -1) continue;
col[i] = 0; Q.push(i);
while (!Q.empty()) {
int pos = Q.front(); Q.pop();
for (int j : G[pos]) {
if (col[j] == -1) { col[j] = (col[pos] ^ 1); Q.push(j); }
else if (col[j] == col[pos]) flag = true;
}
if (pos % KAISOU >= 1) {
if (col[pos - 1] == -1) { col[pos - 1] = col[pos]; Q.push(pos - 1); }
else if (col[pos - 1] != col[pos]) flag = true;
}
if (pos%KAISOU <= KAISOU - 2) {
if (col[pos + 1] == -1) { col[pos + 1] = col[pos]; Q.push(pos + 1); }
else if (col[pos + 1] != col[pos]) flag = true;
}
if (m_back[pos] >= 0) {
int j = m_back[pos];
if (col[j] == -1) { col[j] = col[pos]; Q.push(j); }
else if (col[j] != col[pos]) flag = true;
}
if (m_front[pos] >= 0) {
int j = m_front[pos];
if (col[j] == -1) { col[j] = col[pos]; Q.push(j); }
else if (col[j] != col[pos]) flag = true;
}
}
components++;
}
int ans = 1;
for (int i = 0; i < components; i++) { ans *= 2; ans %= 1000000007; }
if (flag == true) ans = 0;
cout << ans << endl;
return 0;
}
