#pragma GCC optimize("Ofast,unroll-loops,fast-math")
#include<bits/stdc++.h>
using namespace std;
typedef long long ll ;
#define pll pair<ll , ll >
#define all(x) (x).begin(),(x).end()
#define SZ(x) (ll)(x).size()
#define X   first
#define Y   second
#define mp  make_pair
#define pii pair<int , int>
#define vec vector
#define file_io freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);
#define migmig ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define pb push_back
ll poww(ll a, ll b, ll md) {
    return (!b ? 1 : (b & 1 ? a * poww(a * a % md, b / 2, md) % md : poww(a * a % md, b / 2, md) % md));
}
const int maxn = 1000*100+5 ;
const ll inf = 9223372036854775807 ;
const ll mod = 1e9 + 7 ;
const int lg = 20 ;

int main()
{
	migmig ;
	ll v ,  t , s , d ; 
	cin>>v>>t>>s>>d ; 
	if(d < t * v || d > s * v){
		cout<<"Yes" ; 
	}else cout<<"No" ; 
}









  #include<bits/stdc++.h>
  using namespace std;
  using ll = long long;
  #define rep(i,f,n) for(ll i=(f); (i) < (n); i++)
  #define repe(i,f,n) for(ll i=(f); (i) <= (n); i++)
  #define repc(i,f,n) for(char i=(f); (i) <= (n); i++)
  #define PI 3.14159265358979323846264338327950L
  #define debug(x) cout<<#x<<" :: "<<x<<"\n";
  #define debug2(x,y) cout<<#x<<" :: "<<x<<"\t"<<#y<<" :: "<<y<<"\n";
  #define debug3(x,y,z) cout<<#x<<" :: "<<x<<"\t"<<#y<<" :: "<<y<<"\t"<<#z<<" :: "<<z<<"\n";
  #define P pair<int, int>
  #define Pl pair<ll, ll>
  #define dvec vector<vector<ll>>
  #define OUT(x) cout << x << endl; return 0;
  //printf("%.10f\n")
  //cout << fixed << setprecision(10);
  template<class T> inline bool chmax(T& a, T b){if (a < b) { a = b; return true; } return false;}
  template<class T> inline bool chmaxe(T& a, T b){if (a <= b) { a = b; return true; } return false;}
  template<class T> inline bool chmin(T& a, T b){if (a > b) { a = b; return true; } return false;}
  const ll MOD = 1000000007ll;
  const ll INF = 1e+18;
  const int iINF = 1e9;
  const double EPS = 1e-8;


  int main()
{
  ll N; cin >> N;
  vector<ll> A(N);
  rep(i, 0, N)cin >> A[i];
  vector<ll> B(N);
  rep(i, 0, N)cin >> B[i];

  ll ans = 0;
  rep(i, 0, N){
    ans += A[i] * B[i];
  }

  if(ans == 0) cout << "Yes" << endl;
  else cout << "No" << endl;
}