/*
[templates]: 
duipai
compre
addhis
floor_sum
matrix
network_flow
inter
polynomial
subset poly
lca
bitset
valuesgt
fenwick
erbitree
segment
mcmf
primal_dual
centroid
add0cnt
euler
basis
phi
*/
//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx")
#include<bits/stdc++.h>
using namespace std;
#define int long long
//use ll instead of int.
#define f(i, a, b) for(int i = (a); i <= (b); i++)
#define cl(i, n) i.clear(),i.resize(n);
#define endl '\n'
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef array<int, 2> aii; 
typedef array<int, 3> aiii; 
const int inf = 1e18;
//#define cerr if(false)cerr
//#define freopen if(false)freopen
mt19937 rng(std::chrono::high_resolution_clock::now().time_since_epoch().count()); 
int rnd(int l, int r) {return rng() % (r-l+1) + l; }
#define watch(x) cerr  << (#x) << ' '<<'i'<<'s'<<' ' << x << endl
void pofe(int number, int bitnum) {
    string s; f(i, 0, bitnum) {s += char(number & 1) + '0'; number >>= 1; } 
    reverse(s.begin(), s.end()); cerr << s << endl; 
    return;
}
double runtime() {return 1.0*clock()/CLOCKS_PER_SEC;}
template <typename TYP> void cmax(TYP &x, TYP y) {if(x < y) x = y;}
template <typename TYP> void cmin(TYP &x, TYP y) {if(x > y) x = y;}
//调不出来给我对拍！
//use std::array.
const int N=2e5;
int n;
struct node {int x,y;double ang;} a[N+10]; 
vector<int> tb; 
int cross(aii x,aii y) {
    return x[0]*y[1]-x[1]*y[0]; 
}
bool judge(node x,node y,node z) {
    return cross({x.x-y.x,x.y-y.y},{z.x-y.x,z.y-y.y})>=0; 
}
signed main() {
    ios::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    //freopen("X.in","r",stdin);
    //freopen("X.out","w",stdout);
    //freopen("X.ear","w",stderr);
    //time_t start = clock();
    //think twice,code once.
    //think once,debug forever.
    cin>>n; f(i,1,n)cin>>a[i].x>>a[i].y; 
    sort(a+1,a+n+1,[&](node x,node y) {return (x.x<y.x)||(x.x==y.x&&x.y<y.y);});
    f(i,2,n)a[i].ang=atan2(a[i].y-a[1].y,a[i].x-a[1].x);
    sort(a+2,a+n+1,[&](node x,node y) {return x.ang<y.ang;});
    tb.push_back(1); 
    f(i,2,n) {
        while(tb.size() >= 2) {
            if(judge(a[*prev(--tb.end())],a[tb.back()],a[i])) tb.pop_back(); 
            else break; 
        }
        tb.push_back(i); 
    }
    if(tb.size()==n) {
        cout << "Yes\n"; 
    }
    else {
        cout << "No\n";
    }
    //time_t finish = clock();
    //cout << "time used:" << (finish-start) * 1.0 / CLOCKS_PER_SEC <<"s"<< endl;
    return 0;
}