#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
istream &operator>>(istream &is, modint &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint &a) { return os << a.val(); }
istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); }
istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); } 

typedef long long ll;
typedef vector<vector<int>> Graph;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define FOR(i,l,r) for (int i = l;i < (int)(r); i++)
#define rep(i,n) for (int i = 0;i < (int)(n); i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define my_sort(x) sort(x.begin(), x.end())
#define my_max(x) *max_element(all(x))
#define my_min(x) *min_element(all(x))
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const int INF = (1<<30) - 1;
const ll LINF = (1LL<<62) - 1;
const int MOD = 998244353;
const int MOD2 = 1e9+7;
const double PI = acos(-1);
vector<int> di = {1,0,-1,0};
vector<int> dj = {0,1,0,-1};

#ifdef LOCAL
#  include <debug_print.hpp>
#  define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define debug(...) (static_cast<void>(0))
#endif

struct P{
    ll x,y;
};
P operator+(const P &a, const P &b){ return P{a.x + b.x, a.y + b.y};}
P operator-(const P &a, const P &b){ return P{a.x - b.x, a.y - b.y};}
bool operator<(const P &a, const P &b){ 
    if (a.x == b.x) return a.y < b.y;
    else return a.x < b.x;
}
ll cross(P a, P b){
    return a.x * b.y - a.y * b.x;
}

vector<P> convex_hull(vector<P> &ps){
    int n = ps.size();
    sort(all(ps));
    int k = 0;
    vector<P> ch(2*n);
    // 下側凸包
    for(int i=0;i<n;i++){
        while(k > 1 && cross((ch[k-1] - ch[k-2]), (ps[i] - ch[k - 1])) <= 0) k--;
        ch[k++] = ps[i];
    }
    // 上側凸包
    for(int i=n-2,t=k;i>=0;i--){
        while(k > t && cross((ch[k-1] - ch[k-2]), (ps[i] - ch[k - 1])) <= 0) k--;
        ch[k++] = ps[i];
    }
    ch.resize(k-1);
    return ch;
}

ll area2(vector<P> &ps){
    int n = ps.size();
    ll res = 0;
    for(int i=1;i<n-1;i++){
        res += cross((ps[i] - ps[0]), (ps[i+1] - ps[0]));
    }
    return res;
}

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);

    int N; cin >> N;
    vector<P> V;
    rep(i, N){
        int X, Y; cin >> X >> Y;
        V.push_back({X, Y});
    }

    vector<P> C = convex_hull(V);
    cout << ((int)C.size() == N ? "Yes" : "No") << endl;
}