#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define f first
#define s second
#define pb push_back
#define ep emplace
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define uniquev(v) sort(all(v)), (v).resize(unique(all(v)) - (v).begin())
#define mem(f,x) memset(f , x , sizeof(f))
#define sz(x) (ll)(x).size()
#define __lcm(a, b) (1ll * ((a) / __gcd((a), (b))) * (b))
#define mxx *max_element
#define mnn *min_element
#define cntbit(x) __builtin_popcountll(x)
#define len(x) (int)(x.length())
const int N = 1e6 + 10;
int f[N];
void upd(int i, int x) {
for (; i < N; i += i & (-i))
f[i] += x;
}
int get(int i) {
int s = 0;
for (; i; i -= i & (-i))
s += f[i];
return s;
}
ll solve() {
vector <pair <int, int>> seg;
int n;
cin >> n;
for (int i = 1; i <= n; i++) {
int a, b;
cin >> a >> b;
seg.pb({a, b});
}
sort(all(seg));
stack <int> st;
for (int i = n - 1; i >= 0; i--) {
while (sz(st) && seg[i].s > seg[st.top()].s)
st.pop();
if (get(seg[i].s))
return 0;
if (sz(st)) {
int nxt = st.top();
if (seg[i].s > seg[nxt].f) {
upd(seg[nxt].f, 1);
upd(seg[i].s, -1);
}
}
st.push(i);
}
set <int> save;
int cnt = 0;
for (int i = 0; i < n; i++) {
auto it = save.lower_bound(seg[i].f);
if (it == save.end() || *it > seg[i].s) {
cnt++;
}
save.insert(seg[i].s);
}
ll ans = 1, mod = 1e9 + 7;
for (int i = 1; i <= cnt; i++) {
ans = (ans + ans) % mod;
}
return ans;
}
/*
5
1 4
2 10
3 5
6 9
7 8
*/
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t = 1;
//cin >> t;
while (t--) {
cout << solve() << '\n';
}
return 0;
}
