#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int MOD = 1e9 + 7;
const int INF = 1e9;
const int M = (1 << 21);
int n;
vector<int> mn_ver;
vector<int> mx_ver;
vector<pair<int, int>> segs;
int mn(int x, int y) {
return (segs[x].first < segs[y].first ? x : y);
}
int mx(int x, int y) {
return (segs[x].second > segs[y].second ? x : y);
}
void add(int ver) {
int pos = segs[ver].second;
for(pos += M, mn_ver[pos] = ver; pos > 1; pos >>= 1)
mn_ver[pos >> 1] = mn(mn_ver[pos], mn_ver[pos ^ 1]);
pos = segs[ver].first;
for(pos += M, mx_ver[pos] = ver; pos > 1; pos >>= 1)
mx_ver[pos >> 1] = mx(mx_ver[pos], mx_ver[pos ^ 1]);
}
void del(int ver) {
int pos = segs[ver].second;
for(pos += M, mn_ver[pos] = n; pos > 1; pos >>= 1)
mn_ver[pos >> 1] = mn(mn_ver[pos], mn_ver[pos ^ 1]);
pos = segs[ver].first;
for(pos += M, mx_ver[pos] = n; pos > 1; pos >>= 1)
mx_ver[pos >> 1] = mx(mx_ver[pos], mx_ver[pos ^ 1]);
}
int get1(int i) {
int ql = segs[i].first + 1, qr = segs[i].second - 1;
int res_ver = n;
for(ql += M, qr += M + 1; ql < qr; ql >>= 1, qr >>= 1) {
if(ql & 1) {
res_ver = mn(res_ver, mn_ver[ql++]);
}
if(qr & 1) {
res_ver = mn(res_ver, mn_ver[--qr]);
}
}
return res_ver;
}
int get2(int i) {
int ql = segs[i].first + 1, qr = segs[i].second - 1;
int res_ver = n;
for(ql += M, qr += M + 1; ql < qr; ql >>= 1, qr >>= 1) {
if(ql & 1) {
res_ver = mx(res_ver, mx_ver[ql++]);
}
if(qr & 1) {
res_ver = mx(res_ver, mx_ver[--qr]);
}
}
return res_ver;
}
int cl[M];
void dfs(int cur, int color) {
cl[cur] = color;
del(cur);
int next = get1(cur);
while(segs[next].first < segs[cur].first) {
dfs(next, 3 - color);
next = get1(cur);
}
next = get2(cur);
while(segs[next].second > segs[cur].second) {
dfs(next, 3 - color);
next = get2(cur);
}
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin >> n;
mn_ver.assign(2 * M, n);
mx_ver.assign(2 * M, n);
segs.resize(n + 1);
segs[n] = {INF, -INF};
for(int i = 0; i < n; i++) {
cin >> segs[i].first >> segs[i].second;
add(i);
}
int ans = 1;
for(int i = 0; i < n; i++) {
if(cl[i]) continue;
dfs(i, 1);
ans = (ans * 2) % MOD;
}
vector<int> t[2];
for(int i = 0; i < n; i++) {
t[cl[i] - 1].push_back(i);
}
sort(t[0].begin(), t[0].end(), [&](int x, int y) {
if(segs[x].second != segs[y].second) return segs[x].second < segs[y].second;
return segs[x].first > segs[y].first;
});
sort(t[1].begin(), t[1].end(), [&](int x, int y) {
if(segs[x].second != segs[y].second) return segs[x].second < segs[y].second;
return segs[x].first > segs[y].first;
});
for(int c : t[0]) {
add(c);
int v = get1(c);
if(segs[v].first < segs[c].first) {
cout << 0;
return 0;
}
}
for(int c : t[0]) del(c);
for(int c : t[1]) {
add(c);
int v = get1(c);
if(segs[v].first < segs[c].first) {
cout << 0;
return 0;
}
}
cout << ans;
}
