#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
#define rep3(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define rep2(i, a, b) rep3(i, a, b, 1)
#define rep1(i, n) rep2(i, 0, n)
#define rep0(n) rep1(aaaaa, n)
#define ov4(a, b, c, d, name, ...) name
#define rep(...) ov4(__VA_ARGS__, rep3, rep2, rep1, rep0)(__VA_ARGS__)
#define per(i, a, b) for (ll i = (a) - 1; i >= (b); i--)
#define fore(e, v) for (auto&& e : v)
#define all(a) begin(a), end(a)
#define sz(a) (int)(size(a))
#define lb(v, x) (lower_bound(all(v), x) - begin(v))
#define eb emplace_back

template <typename T, typename S>
bool chmin(T& a, const S& b) {
  return a > b ? a = b, 1 : 0;
}
template <typename T, typename S>
bool chmax(T& a, const S& b) {
  return a < b ? a = b, 1 : 0;
}
const int INF = 1e9 + 100;
const ll INFL = 3e18 + 100;
#define i128 __int128_t
struct _ {
  _() { cin.tie(0)->sync_with_stdio(0), cout.tie(0); }
} __;

constexpr ll MOD=998244353;

ll modpow(ll a,ll n){
  long long ret=1%MOD,t=a%MOD;
  while(n>0){
    if(n&1)ret=ret*t%MOD;
    t=t*t%MOD;
    n/=2;
  }
  return ret;
}
vector<int> argsort(const vector<pll> &A) {
  vector<int> ids(A.size());
  iota(all(ids), 0);
  sort(all(ids),
       [&](int i, int j) { return (A[i] == A[j] ? i < j : A[i] < A[j]); });
  return ids;
}
vector<int> convex_hull(const vector<pll> &XY) {
  ll N = XY.size();
  if (N == 0) return {};
  if (N == 1) return {0};
  if (N == 2) return {0, 1};
  vector I = argsort(XY);
  auto check = [&](ll i, ll j, ll k) -> bool {
    auto xi = XY[i].first, yi = XY[i].second;
    auto xj = XY[j].first, yj = XY[j].second;
    auto xk = XY[k].first, yk = XY[k].second;
    auto dx1 = xj - xi, dy1 = yj - yi;
    auto dx2 = xk - xj, dy2 = yk - yj;
    ll det = dx1 * dy2 - dy1 * dx2;
    // return det >= 0; 辺上の点を含む場合
    return det > 0;
  };
  auto calc = [&]() {
    vector<int> P;
    for (auto &&k : I) {
      if (P.size() && XY[P.back()] == XY[k]) continue;
      while (P.size() > 1) {
        auto i = P[P.size() - 2];
        auto j = P[P.size() - 1];
        if (check(i, j, k)) break;
        P.pop_back();
      }
      P.push_back(k);
    }
    return P;
  };

  // 上側
  vector<int> P;
  {
    vector<int> Q1 = calc();
    P.insert(P.end(), all(Q1));
  }

  // 下側
  {
    if (!P.empty()) P.pop_back();
    reverse(all(I));
    vector<int> Q2 = calc();
    P.insert(P.end(), all(Q2));
  }

  if (P.size() >= 2 && XY[P[0]] == XY[P.back()]) P.pop_back();
  return P;
}

int main(){
  int N;
  cin>>N;
  vector<pll> P(N);
  fore(i,P)cin>>i.first>>i.second;
  cout<<(sz(convex_hull(P))==N?"Yes\n":"No\n");
}