#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;

const int MAXN = 1e2 + 10;
const int INF = 0x3f3f3f3f;
const ll INFLL = 0x3f3f3f3f3f3f3f3f;

random_device seed;
mt19937 rnd(seed());
mt19937_64 rnd_64(seed());

const double eps = 1e-8;
int sgn(double x) {
    return x < -eps ? -1 : (x > eps ? 1 : 0);
}

struct Point {
    ll x, y;
    Point operator - (const Point &a) {
        return {x - a.x, y - a.y};
    }
};

ll dot(const Point &a, const Point &b) {
    return a.x * b.x + a.y * b.y;
}

ll det(const Point &a, const Point &b) {
    return a.x * b.y - a.y * b.x;
}

double len(const Point &a) {
    return sqrt(a.x * a.x + a.y * a.y);
}

double theta(const Point &a, const Point &b) {
    return acos(1.0 * dot(a, b) / len(a) / len(b));
}

void solve () {
    int n;
    cin >> n;
    vector<Point> p(n);
    double sum = 0;
    for(int i = 0; i < n; ++i) cin >> p[i].x >> p[i].y;
    for(int i = 0; i < n; ++i) {
        int i1 = i, i2 = (i + 1) % n, i3 = (i + 2) % n;
        Point v1 = p[i2] - p[i1], v2 = p[i3] - p[i2];

        if(sgn(det(v1, v2)) == 0) {
            cout << "No\n";
            return;
        }

        sum += theta(v1, v2);
    }

    if(sgn(sum - 2 * acos(-1)) <= 0) cout << "Yes\n";
    else cout << "No\n";
}

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

    int Task = 1;
    while (Task--) {
        solve();
    }

    return 0;
}