#include<bits/stdc++.h>
using namespace std;
 int main(){
     
  int v,t,s,d;
    cin>>v>>t>>s>>d;
    int st=v*t;
    int en=v*s;
    if(d<st||d>en)
    cout<<"Yes";
    else
    cout<<"No";
    return 0;
}
#include<iostream>

using namespace std;

int main()
{
   long long n,m,t;
   cin>>n>>m>>t;
   long long answer = n;
   int start,end;
   cin>>start>>end;
   answer -= (start);
   if(answer<1){
      cout<<"No"<<endl;
      return 0;
   }
   answer+= (end-start);
   if(answer>n){
      answer=n;
   }
   for(int i = 1 ; i < m ; i++){
      long long l = end;
      cin>>start>>end;
      answer-=(start-l);
      if(answer<1){
         cout<<"No"<<endl;
         return 0;
      }
      answer+= (end-start);
      if(answer>n){
         answer=n;
      }
   }
   answer-=(t-end);
   answer<=0 ? cout<<"No":cout<<"Yes"<<endl;
   return 0;
}
