n,t,k,d=map(int,input().split())
if (n%k == 0):
o=n/k
else:
o= int(n/k)+1
if ((o*t) > (t+d)):
print('YES')
else:
print('NO')#include <bits/stdc++.h>
typedef long long ll;
typedef long double ld;
#define vector<int> vi;
#define vector<ll> vll;
#define all(x) (x).begin(),(x).end()
#define pb push_back
#define SZ(x) (int)x.size()
#define ALL(x) (x).begin(),(x).end()
#define SORT(x) sort((x).begin(),(x).end())
using namespace std;
int main()
{
int n,t,k,d,time=0;
cin >>n>>t>>k>>d;
int cake=n,round=t,per=k;
for(int i=1; cake>0; i++)
{
time+=round;
cake-=per;
}
int time2=0,time3=d;
for(int i=1; n>0; i++)
{
time2+=t;
n-=k;
if(time2>d)
{
time3+=t;
n-=k;
}
}
int x=max(time2,time3);
if(x<time) cout<<"YES"<<endl;
else cout<<"NO"<<endl;
return 0;
}1095A - Repeating Cipher | 630F - Selection of Personnel |
630K - Indivisibility | 20B - Equation |
600B - Queries about less or equal elements | 1015A - Points in Segments |
1593B - Make it Divisible by 25 | 680C - Bear and Prime 100 |
1300A - Non-zero | 1475E - Advertising Agency |
1345B - Card Constructions | 1077B - Disturbed People |
653A - Bear and Three Balls | 794A - Bank Robbery |
157A - Game Outcome | 3B - Lorry |
1392A - Omkar and Password | 489A - SwapSort |
932A - Palindromic Supersequence | 433A - Kitahara Haruki's Gift |
672A - Summer Camp | 1277A - Happy Birthday Polycarp |
577A - Multiplication Table | 817C - Really Big Numbers |
1355A - Sequence with Digits | 977B - Two-gram |
993A - Two Squares | 1659D - Reverse Sort Sum |
1659A - Red Versus Blue | 1659B - Bit Flipping |