//#pragma GCC optimize("O3, unroll-loops")
//#pragma GCC target("avx2, bmi, bmi2, lzcnt, popcnt")
#include <bits/stdc++.h>
using namespace std;
#define V vector
#define all0(x) (x).begin(), (x).end()
#define all1(x) (x).begin() + 1, (x).end()
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
#define cin std::cin
#define cout std::cout
typedef long long LL;
typedef pair<int, int> pi;
typedef pair<LL, LL> pl;
#ifdef LOCAL
#include "C:/Users/lijia/Desktop/vscode/algo/debug.h"
#else
#define debug(...) 42
#endif

//const int MN = 2e5 + 20;//MaxN 记得改一下
const int INF = 2e9 + 1000;//INF
const LL INFLL = 8e18 + 1000;//INF long long 
mt19937 mrand(random_device{}());
//模板区域~~~~~~~
#define db LL
const db EPS = 1e-9;
inline int sign(db a){ return a < -EPS ? -1 : a > EPS; }
inline int cmp(db a, db b){ return sign(a - b); }

struct P {
    db x, y;
    P operator+(P o){return {x + o.x, y + o.y};}
    P operator-(P o){return {x - o.x, y - o.y};}
    P operator*(db k){return {x * k, y * k};}
    P operator/(db k){return {x / k, y / k};}

    bool operator<(P o) const{
        int c = cmp(x, o.x);
        if (c) return c == -1;
        return cmp(y, o.y) == -1;
    }
    
    bool operator==(P o) const{
        return cmp(x,o.x) == 0 && cmp(y,o.y) == 0;
    }

    db dot(P o){ return x * o.x + y * o.y; }
    db det(P o){ return x * o.y - y * o.x; }
    
    db abs(){ return sqrt(abs()); }
    db abs2(){ return x * x + y * y; }
    db distTo(P p){ return (*this - p).abs(); }
    db alpha(){ return atan2(y, x); }
    P rot90(){ return {-y, x}; }
    P unit(){ return *this / abs(); }
    int quad() const {return sign(y) == 1 || (sign(y) == 0 && sign(x) >= 0); }
    P rot(db an){ return {x * cos(an) - y * sin(an), x * sin(an) + y * cos(an)}; }
    bool bef(P p){ return quad() < p.quad() || det(p) > 0; }//trying 

    void show(){ cout << "(" << x << "," << y << ")" << endl; }
    void read(){ cin >> x >> y; }
};
#define cross(p1, p2, p3) ((p2.x - p1.x) * (p3.y - p1.y) - (p3.x - p1.x) * (p2.y - p1.y))
#define crossOp(p1, p2, p3) sign(cross(p1, p2, p3))

//恰好一个交点
bool chkLL(P p1, P p2, P q1, P q2){
    db a1 = cross(q1, q2, p1), a2 = -cross(q1, q2, p2);
    return sign(a1 + a2) != 0;
}

P getLL(P p1, P p2, P q1, P q2){
    db a1 = cross(q1, q2, p1), a2 = -cross(q1, q2, p2);
    return (p1 * a2 + p2 * a1) / (a1 + a2);
}

bool intersect(db l1, db r1, db l2, db r2){
    if(l1 > r1) swap(l1, r1);
    if(l2 > r2) swap(l2, r2);
    return !(cmp(r1, l2) == -1 || cmp(r2, l1) == -1);
}

bool isSS(P p1, P p2, P q1, P q2){
    return intersect(p1.x, p2.x, q1.x, q2.x) && 
            intersect(p1.y, p2.y, q1.y, q2.y) &&
            crossOp(p1, p2, q1) * crossOp(p1, p2, q2) <= 0 &&
            crossOp(q1, q2, p1) * crossOp(q1, q2, p2) <= 0;
}

bool isSS_strict(P p1, P p2, P q1, P q2){
    return crossOp(p1, p2, q1) * crossOp(p1, p2, q2) < 0 &&
            crossOp(q1, q2, p1) * crossOp(q1, q2, p2) < 0;
}

bool isMid(db a, db m, db b){
    return sign(a - m) == 0 || sign(b - m) == 0 || (a < m != b < m);
}   

bool isMid(P a, P m, P b){
    return isMid(a.x, m.x, b.x) && isMid(a.y, b.y, m.y);
}

bool onSeg(P p1, P p2, P q){
    return crossOp(p1, p2, q) == 0 && isMid(p1, q, p2);
}

bool onSeg_strict(P p1, P p2, P q){
    return crossOp(p1, p2, q) == 0 &&
        sign((q - p1).dot(p1 - p2)) * sign((q - p2).dot(p1 - p2)) < 0;
}

P proj(P p1, P p2, P q){
    P dir = p2 - p1;
    return p1 + dir * (dir.dot(q - p1) / dir.abs2());
}

P reflect(P p1, P p2, P q){
    return proj(p1, p2, q) * 2 - q;
}

db nearest(P p1, P p2, P q){
    if(p1 == p2) return p1.distTo(q);
    P h = proj(p1, p2, q);
    if(isMid(p1, h, p2))
        return q.distTo(h);
    return min(p1.distTo(q), p2.distTo(q));
}

db dissSS(P p1, P p2, P q1, P q2){
    if(isSS(p1, p2, q1, q2)) return 0;
    return min({nearest(p1, p2, q1), nearest(p1, p2, q2),
                nearest(q1, q2, p1), nearest(q1, q2, p2)});
} 
//模板结束~~~~~~~

void solve() {
    int n; cin >> n;
    V<P> a(n * 2 + 1);
    for(int i = 1; i <= n; i++) {
        a[i].read();
        a[i + n] = a[i];
    }
    auto ok = [&n] (V<P> a) -> bool {
        P mn = {INFLL, INFLL};
        int s;
        for(int i = 1; i <= n; i++){
            if(a[i] < mn) {
                mn = a[i];
                s = i;
            }
        }
        debug(s);
        for(int i = n; i >= 1; i--) {
            a[i] = a[i] - a[1];
        }
        for(int i = s + 1; i < s + n - 1; i++) {
            if(a[i].det(a[i + 1]) <= 0) return 0;
            if((a[i] - a[i - 1]).det(a[i + 1] - a[i]) <= 0) return 0;
        }
        return 1;
    };
    if(ok(a)) cout << "Yes\n";
    else {
        reverse(all1(a));
        cout << (ok(a) ? "Yes\n" : "No\n");
    }
}
int32_t main() {
#ifndef LOCAL
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#endif
#ifdef LOCAL
   freopen("C:/Users/lijia/Desktop/vscode/in.in", "r", stdin);
   freopen("C:/Users/lijia/Desktop/vscode/out.out", "w", stdout);
#endif
    int tt = 1;
    //cin >> tt;
    while (tt--) 
    solve();
}