#include <cstdio>
#include <cmath>
#include <algorithm>

typedef double ld;

struct Point{
    ld x, y, ang;
    Point operator + (const Point &oth) const { return { x+oth.x, y+oth.y }; }
    Point operator - (const Point &oth) const { return { x-oth.x, y-oth.y }; }
    Point operator * (const ld &p) const { return { x*p, y*p }; }
    Point operator / (const ld &p) const { return { x/p, y/p }; }
    bool operator == (const Point &oth) const { return x == oth.x && y == oth.y; }
};

ld dot(const Point &a, const Point &b){
    return a.x * b.x + a.y * b.y;
}
ld det(const Point &a, const Point &b){
    return a.x * b.y - a.y * b.x;
}
ld dis(const Point &a){
    return sqrt(a.x*a.x + a.y*a.y);
}
ld dis(const Point &a, const Point &b){
    return sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y));
}

ld vec_angle(const Point &a, const Point &b){
    // 适用于向量 a 和 b 求角
    // return acos(dot(a, b) / (dis(a) * dis(b)));
    return atan2(a.y, a.x) - atan2(b.y, b.x);
}

const int maxn = 2e5 + 5;
int n;
Point p[maxn], tmp[2][maxn];

int stk[maxn], top;

int main(){
    scanf("%d", &n);
    for(int i = 1; i <= n; i++) scanf("%lf%lf", &p[i].x, &p[i].y);
    int id = 1;
    for(int i = 2; i <= n; i++) if(p[i].y < p[1].y || (p[i].y == p[1].y && p[i].x < p[1].x)) id = i;
    // printf("%d\n", id);
    for(int i = 1; i <= n; i++) tmp[0][i] = p[(i+id-1) <= n ? (i+id-1) : ((i+id)%n+1)];
    for(int i = 1; i <= n; i++) tmp[1][i] = p[(id-i+1) >= 1 ? (id-i+1) : ((id-i+n)%n+1)];

    std::swap(p[1], p[id]);

    // for(int i = 1; i <= n; i++) printf("%lf %lf\n", tmp[i].x, tmp[i].y);

    for(int i = 2; i <= n; i++) p[i].ang = atan2(p[i].y - p[1].y, p[i].x - p[1].x);
    std::sort(p+2, p+1+n, [&](Point a, Point b){ return a.ang == b.ang ? dis(a, p[1]) < dis(b, p[1]) : a.ang < b.ang; });
    stk[++top] = 1;
    for(int i = 2; i <= n; i++){
        while(top > 1 && det(p[stk[top]] - p[stk[top-1]], p[i] - p[stk[top]]) <= 0) top--;
        stk[++top] = i;
    }
    // for(int i = 1; i <= top; i++) printf("%d%c", stk[i], " \n"[i==top]);
    if(top < n){ puts("No"); return 0; }
    for(int i = 1; i <= n; i++){
        // printf("Compare (%lf, %lf) with (%lf, %lf) or (%lf, %lf)\n", p[stk[i]].x, p[stk[i]].y, tmp[0][i].x, tmp[0][i].y, tmp[1][i].x, tmp[1][i].y);
        if(p[stk[i]] == tmp[0][i] || p[stk[i]] == tmp[1][i]) continue;
        // if(n == 128312) printf("Compare (%lf, %lf) with (%lf, %lf) or (%lf, %lf)\n", p[stk[i]].x, p[stk[i]].y, tmp[0][i].x, tmp[0][i].y, tmp[1][i].x, tmp[1][i].y);
        puts("No"); return 0;
    }
    puts("Yes");
    return 0;
}