#include <bits/stdc++.h>
using namespace std;
// #define int long long
const long long modulo = 1e9+7;
const int LIMIT = 1e9;
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int N;
cin >> N;
vector<pair<int,int>> ships(N);
for(auto&[a,b]:ships)cin>>a>>b;
vector<vector<pair<int,int>>> adj(N);
sort(ships.begin(), ships.end());
set<pair<int,int>> active;
set<pair<int,int>> activelightconstrain;
vector<bool> lightcontrain(N);
auto helper_remove_until = [&](int x) {
while(!active.empty() and active.begin()->first<x) {
auto curr = *active.begin();
if(lightcontrain[curr.second])activelightconstrain.erase(curr);
lightcontrain[curr.second]=false;
active.erase(active.begin());
}
if(!active.empty()) {
auto curr = *active.begin();
if(lightcontrain[curr.second])activelightconstrain.erase(curr);
lightcontrain[curr.second]=false;
}
};
auto helper_add = [&](int x) {
auto iter = active.emplace(ships[x].second,x).first;
auto iter2 = activelightconstrain.emplace(ships[x].second,x).first;
lightcontrain[x]=true;
auto nxt = next(iter);
if(nxt!=active.end()) {
lightcontrain[nxt->second]=true;
activelightconstrain.emplace(*nxt);
}
while(activelightconstrain.begin()!=iter2) {
auto curr = *activelightconstrain.begin();
auto pre = prev(active.find(curr));
adj[curr.second].emplace_back(pre->second,0);
adj[pre->second].emplace_back(curr.second,0);
lightcontrain[curr.second]=false;
activelightconstrain.erase(activelightconstrain.begin());
}
if(iter==active.begin())return;
iter = prev(iter);
adj[iter->second].emplace_back(x,1);
adj[x].emplace_back(iter->second,1);
};
for(int i=0;i<N;i++) {
auto [a,b] = ships[i];
helper_remove_until(a);
helper_add(i);
}
long long ans = 1;
vector visited(N,-1);
bool works = true;
function<void(int,int)> dfs = [&](int x,int colour) {
if(visited[x]!=-1) {
if(visited[x]!=colour)works=false;
return;
}
visited[x]=colour;
for(auto&[v,wt]:adj[x])dfs(v,colour^wt);
};
for(int i=0;i<N;i++)if(visited[i]==-1){
ans<<=1;
ans%=modulo;
dfs(i,0);
}
if(!works)ans=0;
cout << ans << '\n';
}
