#include<bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;

#define all(v) v.begin(),v.end()
using ll = long long;
using ull = unsigned long long;
using lll = __int128;
using vll=vector<ll>;
using vvll = vector<vector<ll>>;
using P = pair<ll,ll>;
using vp=vector<pair<ll, ll>>;
//using mint=modint1000000007;
//using mint=modint998244353;

const ll INF=1ll<<60;
ll mod10=1e9+7;
ll mod99=998244353;
const double PI = acos(-1);

#define rep(i,n) for (ll i=0;i<n;++i)
#define per(i,n) for(ll i=n-1;i>=0;--i)
#define rep2(i,a,n) for (ll i=a;i<n;++i)
#define per2(i,a,n) for (ll i=a;i>=n;--i)

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return true; } return false; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return true; } return false; }



bool solve(){
    ll N;cin>>N;
    vll X(N),Y(N);rep(i,N) cin>>X[i]>>Y[i];
    
    ll i=0;
    vp XY(N);rep(i,N) XY[i].first=X[i],XY[i].second=Y[i];
    sort(all(XY));
    rep(i,N){
        X[i]=XY[i].first;
        Y[i]=XY[i].second;
    }
    per(i,N){
        X[i]-=X[0];
        Y[i]-=Y[0];
    }
     i=0;
    for(auto& [a,b]:XY) a=X[i],b=Y[i],i++;
    vll ind(N);rep(i,N) ind[i]=i;
    auto f = [&](int i,int j) -> bool {
        ll ax=XY[i].first,ay=XY[i].second;
        ll bx=XY[j].first,by=XY[j].second;
        ll areaa=!((ay>0)||(ay==0&&ax>=0));
        ll areab=!(by>0||(by==0&&bx>=0));
            
        return (areaa==areab?ax*by-ay*bx>0:areaa<areab);
            
    };
    sort(all(ind),f);
    assert(X[ind[0]]==0&&Y[ind[0]]==0);
    rep(ii,N){
        ll i=ind[ii];
        ll j=ind[(ii+1)%N],k=ind[(ii+2)%N];
        ll x1=X[k]-X[j],y1=Y[k]-Y[j];
        ll x2=X[i]-X[j],y2=Y[i]-Y[j];
        if(x1*y2-x2*y1<=0){
            cout<<"No"<<endl;
            return 0;
        }
    }
    cout<<"Yes"<<endl;
    return 0;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll T=1;//cin>>T;
    rep(i,T) solve();
}