// g++-14 1.cpp -std=c++20 -O2 -I .
#include <bits/stdc++.h>
using namespace std;

#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#include<ext/pb_ds/tag_and_trait.hpp>
using namespace __gnu_pbds;

#include <atcoder/dsu>
using namespace atcoder;

using ll = long long;
using ld = long double;
 
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vld = vector<ld>;
using vvld = vector<vld>;
using vst = vector<string>;
using vvst = vector<vst>;

#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define pq_big(T) priority_queue<T,vector<T>,less<T>>
#define pq_small(T) priority_queue<T,vector<T>,greater<T>>
#define all(a) a.begin(),a.end()
#define rep(i,start,end) for(ll i=start;i<(ll)(end);i++)
#define per(i,start,end) for(ll i=start;i>=(ll)(end);i--)
#define uniq(a) sort(all(a));a.erase(unique(all(a)),a.end())

random_device seed;
mt19937_64 randint(seed());

ll grr(ll mi, ll ma) { // [mi, ma)
    return mi + randint() % (ma - mi);
}

// onEdge を 0,1 にすると辺上を 拾わない/拾う にできます

#include <vector>
#include <algorithm>

long long cross_for_convex_hull(const std::pair<long long,long long> &a,const std::pair<long long,long long> &b){
  return a.first*b.second-a.second*b.first;
}

std::pair<long long,long long> sub_for_convex_hull(const std::pair<long long,long long> &a,const std::pair<long long,long long> &b){
  return {a.first-b.first,a.second-b.second};
}

// 最も左(タイブレークは最も下)から反時計回り
std::vector<std::pair<long long,long long>> convex_hull(const std::vector<std::pair<long long,long long>> &points,bool onEdge=false){
  int n=points.size(),k=0;
  auto p=points;
  const long long limit=onEdge ? 0 : 1;
  if(n<=2)return p;
  std::sort(p.begin(),p.end());
  std::vector<std::pair<long long,long long>> ch(2*n);
  for(int i=0;i<n;ch[k++]=p[i++]){
    while(k>=2&&cross_for_convex_hull(sub_for_convex_hull(ch[k-1],ch[k-2]),sub_for_convex_hull(p[i],ch[k-1]))<limit) --k;
  }
  for(int i=n-2,t=k+1;i>=0;ch[k++]=p[i--]){
    while(k>=t&&cross_for_convex_hull(sub_for_convex_hull(ch[k-1],ch[k-2]),sub_for_convex_hull(p[i],ch[k-1]))< limit) --k;
  }
  ch.resize(k-1);
  return ch;
}

int main(){
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);

  int n;cin>>n;
  vector<pair<ll,ll>> p;
  rep(i,0,n){
    ll x,y;cin>>x>>y;
    p.emplace_back(x,y);
  }
  auto ch=convex_hull(p);
  if(ch.size()==n){
    cout<<"Yes";
  }
  else{
    cout<<"No";
  }
}