This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
/* code by the cute ~~Dengdualang~~ PixelCat owo */
/*     as cute as nacho neko (aka. my wife)!     */
/*     Nhade stay for a night here               */
/*     183234 deng deng deng pixelcat oops       */
/*     (yang wang yesu)*2                        */
/*     ^ some weird stuff. nvm =w=               */
// #pragma GCC optimize("O4,unroll-loops,no-stack-protector")
// #pragma GCC target("avx,avx2,sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,fma")
#include <bits/stdc++.h>
#define int LL  //__int128
#define double long double
using namespace std;
using LL = long long;
using LLL = __int128_t;
using uLL = unsigned long long;
using pii = pair<int, int>;
#define For(i, a, b) for (int i = a; i <= b; i++)
#define Fors(i, a, b, s) for (int i = a; i <= b; i += s)
#define Forr(i, a, b) for (int i = a; i >= b; i--)
#define F first
#define S second
#define L(id) (id * 2 + 1)
#define R(id) (id * 2 + 2)
#define LO(x) (x & (-x))
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define sz(x) ((int)x.size())
#define mkp make_pair
// #define MOD (int)(998244353)
#define MOD (int)((LL)1'000'000'007)
#define INF (int)(4e18)
// #define INF 1e9
#define EPS (1e-6)
#ifdef NYAOWO
#include "library/debug.hpp"
inline void USACO(const string &s) {
    cerr << "USACO: " << s << "\n";
}
#else
#define debug(...)
inline void timer() {}
inline void USACO(const string &s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
#endif
inline void NYA() {
    ios::sync_with_stdio(false);
    cin.tie(0);
}
inline int gcd(int a, int b) {
    return __gcd(a, b);
}
inline int lcm(int a, int b) {
    return a / gcd(a, b) * b;
}
int fpow(int b, int p, const int &mod) {
    int ans = 1;
    while (p) {
        if (p & 1) ans = ans * b % mod;
        p >>= 1;
        b = b * b % mod;
    }
    return ans;
}
int fpow(int b, int p) {
    return fpow(b, p, MOD);
}
template <typename T>
inline void chmin(T &_a, const T &_b) {
    if (_b < _a) _a = _b;
}
template <typename T>
inline void chmax(T &_a, const T &_b) {
    if (_b > _a) _a = _b;
}
// mt19937_64 rng(
//     chrono::steady_clock::now().time_since_epoch().count());
vector<int> adj[2010];
int vis[2010];
bool dfs(int n,int c){
    vis[n]=c;
    bool ac=true;
    for(auto &i:adj[n]){
        if(!vis[i]){
            ac=ac && dfs(i,3-c);
        }else if(vis[i]==vis[n]){
            ac=false;
        }
    }
    return ac;
}
int32_t main() {
    NYA();
    // nyaacho >/////<
    // miku sama bless me >/////<
    int n; cin>>n;
    assert(n<=2000);
    vector<pii> v(n);
    for(auto &i:v) cin>>i.F>>i.S;
    sort(all(v));
    For(i,0,n-1) For(j,i+1,n-1){
        if(v[i].S>v[j].F && v[i].S<v[j].S){
            adj[i].eb(j);
            adj[j].eb(i);
        }
    }
    int ans=1;
    For(i,0,n-1){
        if(!vis[i]){
            ans+=ans;
            if(ans>=MOD) ans-=MOD;
            if(!dfs(i,1)) ans=0;
        }
    }
    cout<<ans<<"\n";
    return 0;
}
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