#ifndef INCLUDED_MAIN
#define INCLUDED_MAIN

#include __FILE__

int main(){
    ll n; cin>>n;
    vector<point> v(n);
    rep(i,n) {
        cin>>v[i].x>>v[i].y;
    }

    ll lowidx=0;
    srep(i,1,n-1) {
        if(v[i].y<v[lowidx].y || (v[i].y==v[lowidx].y && v[i].x<v[lowidx].x)) lowidx=i;
    }
    swap(v[0],v[lowidx]);
    point base=v[0];

    sort(v.begin()+1,v.end(),[&](point& a,point& b) {
        ll cross=Xprod(base,a,b);
        if(cross!=0) return cross>0;
        return distsq(base,a)<distsq(base,b);
    }
    );

    vector<point> st;
    st.reserve(n);
    st.pb(v[0]);
    st.pb(v[1]);
    srep(i,2,n-1) {
        while(st.size()>=2 && Xprod(st[st.size()-2],st.back(),v[i])<=0) st.pop_back();
        st.pb(v[i]);
    }
    yn(st.size()==n);
}

/////// library zone ///////
#else
#include <bits/stdc++.h>
#include <atcoder/segtree>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define srep(i,l,r) for(ll i=l;i<=r;i++)
using ll = long long;
using ld = long double;
const ll mod=998244353;
#define vout(v) for(auto i :v) cout<<i<<" ";
#define INF 9223300000000000000ll
#define Winf 5e12
#define nl "\n"
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define vl vector<ll>
#define vc vector<char>
#define pb push_back


struct point {
    ll x;
    ll y;
};

ll Xprod(point &o,point &a,point &b) {
    return (a.x-o.x)*(b.y-o.y)-(a.y-o.y)*(b.x-o.x);
}


ll distsq(const point& a,const point& b){
    ll dx=a.x-b.x, dy=a.y-b.y;
    return dx*dx+dy*dy;
}

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

void no() { cout<<"No"<<nl;}
void yes() { cout<<"Yes"<<nl;}
void yn(bool a) {
    cout<<(a ? "Yes":"No")<<nl;
}

ll sum(vector<ll>& a) {
    ll ans=0;
    for(auto i:a) ans+=i;
    return ans;
}



ll modpow(ll fl, ll po, ll mode) {  // mode: 0=modなし, 1=modあり
    ll ret=1;
    if (mode) {
        while (po>0) {
            if (po&1) ret=(ret*fl)%mod;
            fl=(fl*fl)%mod;
            po>>=1;
        }
    } else {
        while (po>0) {
            if(po&1) ret*=fl;
            fl*=fl;
            po>>=1;
        }
    }
    return ret;
}

ll modinv(ll a, ll mod) { //拡張Euclidによるmodでの逆元, a*u+mod*v=1を解く
	ll b=mod,u=1,v=0;
	while (b) {
		ll t=a/b;
		a-=t*b;
        swap(a,b);
		u-=t*v;
        swap(u,v);
	}
	u%=mod; 
	if (u < 0) u+=mod;
	return u;
}
#endif