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

std::vector<std::pair<long long,long long>> convex_hull(std::vector<std::pair<long long,long long>> P){
    // Copyright (c) 2023 0214sh7
    // https://github.com/0214sh7/library/
    if(P.size()<=2){
        return P;
    }
    std::vector<std::pair<long long,long long>> H,L,R;
    sort(P.begin(),P.end());
    
    //下半分
    for(int i=0;i<P.size();i++){
        int j=L.size();
        while(j>=2 && (L[j-1].first-L[j-2].first)*(P[i].second-L[j-2].second)<=(L[j-1].second-L[j-2].second)*(P[i].first-L[j-2].first)){
            L.pop_back();
            j--;
        }
        L.push_back(P[i]);
    }
    
    //上半分
    for(int i=P.size()-1;i>=0;i--){
        int j=H.size();
        while(j>=2 && (H[j-1].first-H[j-2].first)*(P[i].second-H[j-2].second)<=(H[j-1].second-H[j-2].second)*(P[i].first-H[j-2].first)){
            H.pop_back();
            j--;
        }
        H.push_back(P[i]);
    }
    
    
    R=L;
    for(int i=1;i<H.size()-1;i++){
        R.push_back(H[i]);
    }
    
    return R;
}

int main() {
	int N; cin >> N;
	vector<pair<long long, long long>> XY(N);
	for (int i = 0; i < N; i++) {
		cin >> XY[i].first >> XY[i].second;
	}
	cout << (convex_hull(XY).size() == N? "Yes" : "No") << endl;
}