import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a=sc.nextInt();
        int b=sc.nextInt();
        int c=sc.nextInt();
        int d=sc.nextInt();
        int x=0;
        int k=0;
        while(true) {
            if (x % 2 == 0) {
                if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                }
            }
            else {
                if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                }
            }
        }
        if(k==1)
            System.out.println("Yes");
        if(k==2)
            System.out.println("No");
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a=sc.nextInt();
        int b=sc.nextInt();
        int c=sc.nextInt();
        int d=sc.nextInt();
        int x=0;
        int k=0;
        while(true) {
            if (x % 2 == 0) {
                if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                }
            }
            else {
                if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                }
            }
        }
        if(k==1)
            System.out.println("Yes");
        if(k==2)
            System.out.println("No");
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a=sc.nextInt();
        int b=sc.nextInt();
        int c=sc.nextInt();
        int d=sc.nextInt();
        int x=0;
        int k=0;
        while(true) {
            if (x % 2 == 0) {
                if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                }
            }
            else {
                if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                }
            }
        }
        if(k==1)
            System.out.println("Yes");
        if(k==2)
            System.out.println("No");
    } main {
        Scanner sc = new Scanner(System.in);
        int a=sc.nextInt();
        int b=sc.nextInt();
        int c=sc.nextInt();
        int d=sc.nextInt();
        int x=0;
        int k=0;
        while(true) {
            if (x % 2 == 0) {
                if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                }
            }
            else {
                if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                }
            }
        }
        if(k==1)
            System.out.println("Yes");
        if(k==2)
            System.out.println("No");
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int a=sc.nextInt(); a sc.nextInt() sc.nextInt sc int b=sc.nextInt(); b sc.nextInt() sc.nextInt sc int c=sc.nextInt(); c sc.nextInt() sc.nextInt sc int d=sc.nextInt(); d sc.nextInt() sc.nextInt sc int x=0; x 0 int k=0; k 0 while(true) {
            if (x % 2 == 0) {
                if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                }
            }
            else {
                if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                }
            }
        } true {
            if (x % 2 == 0) {
                if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                }
            }
            else {
                if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                }
            }
        } if (x % 2 == 0) {
                if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                }
            }
            else {
                if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                }
            } x % 2 == 0 x % 2 x 2 0 {
                if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                }
            } if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                } c > b c b {
                    c -= b;
                    x++;
                } c -= b c b x++ x {
                    k = 1;
                    break;
                } k = 1 k 1 break; {
                if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                }
            } if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                } a > d a d {
                    a -= d;
                    x++;
                } a -= d a d x++ x {
                    k = 2;
                    break;
                } k = 2 k 2 break; if(k==1)
            System.out.println("Yes"); k==1 k 1 System.out.println("Yes") System.out.println System.out System System.out "Yes" if(k==2)
            System.out.println("No"); k==2 k 2 System.out.println("No") System.out.println System.out System System.out "No" String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a=sc.nextInt();
        int b=sc.nextInt();
        int c=sc.nextInt();
        int d=sc.nextInt();
        int x=0;
        int k=0;
        while(true) {
            if (x % 2 == 0) {
                if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                }
            }
            else {
                if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                }
            }
        }
        if(k==1)
            System.out.println("Yes");
        if(k==2)
            System.out.println("No");
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a=sc.nextInt();
        int b=sc.nextInt();
        int c=sc.nextInt();
        int d=sc.nextInt();
        int x=0;
        int k=0;
        while(true) {
            if (x % 2 == 0) {
                if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                }
            }
            else {
                if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                }
            }
        }
        if(k==1)
            System.out.println("Yes");
        if(k==2)
            System.out.println("No");
    }
} Main
import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a=sc.nextInt();
        int b=sc.nextInt();
        int c=sc.nextInt();
        int d=sc.nextInt();
        int x=0;
        int k=0;
        while(true) {
            if (x % 2 == 0) {
                if (c > b) {
                    c -= b;
                    x++;
                } else {
                    k = 1;
                    break;
                }
            }
            else {
                if (a > d) {
                    a -= d;
                    x++;
                } else {
                    k = 2;
                    break;
                }
            }
        }
        if(k==1)
            System.out.println("Yes");
        if(k==2)
            System.out.println("No");
    }
}
