import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();
        int count = 0;
        while (A > 0 && C > 0) {
            if (count % 2 == 0) {
                C = C - B;
            } else {
                A = A - D;
            }
            count++;
        }

        if (A>0) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();
        int count = 0;
        while (A > 0 && C > 0) {
            if (count % 2 == 0) {
                C = C - B;
            } else {
                A = A - D;
            }
            count++;
        }

        if (A>0) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
} Main public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();
        int count = 0;
        while (A > 0 && C > 0) {
            if (count % 2 == 0) {
                C = C - B;
            } else {
                A = A - D;
            }
            count++;
        }

        if (A>0) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    } main {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();
        int count = 0;
        while (A > 0 && C > 0) {
            if (count % 2 == 0) {
                C = C - B;
            } else {
                A = A - D;
            }
            count++;
        }

        if (A>0) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) int A = scanner.nextInt(); A scanner.nextInt() scanner.nextInt scanner int B = scanner.nextInt(); B scanner.nextInt() scanner.nextInt scanner int C = scanner.nextInt(); C scanner.nextInt() scanner.nextInt scanner int D = scanner.nextInt(); D scanner.nextInt() scanner.nextInt scanner int count = 0; count 0 while (A > 0 && C > 0) {
            if (count % 2 == 0) {
                C = C - B;
            } else {
                A = A - D;
            }
            count++;
        } A > 0 && C > 0 A > 0 A 0 C > 0 C 0 {
            if (count % 2 == 0) {
                C = C - B;
            } else {
                A = A - D;
            }
            count++;
        } if (count % 2 == 0) {
                C = C - B;
            } else {
                A = A - D;
            } count % 2 == 0 count % 2 count 2 0 {
                C = C - B;
            } C = C - B C C - B C B {
                A = A - D;
            } A = A - D A A - D A D count++ count if (A>0) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        } A>0 A 0 {
            System.out.println("Yes");
        } System.out.println("Yes") System.out.println System.out System System.out "Yes" {
            System.out.println("No");
        } 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 scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();
        int count = 0;
        while (A > 0 && C > 0) {
            if (count % 2 == 0) {
                C = C - B;
            } else {
                A = A - D;
            }
            count++;
        }

        if (A>0) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
} public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();
        int count = 0;
        while (A > 0 && C > 0) {
            if (count % 2 == 0) {
                C = C - B;
            } else {
                A = A - D;
            }
            count++;
        }

        if (A>0) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
} Main
import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();
        int count = 0;
        while (A > 0 && C > 0) {
            if (count % 2 == 0) {
                C = C - B;
            } else {
                A = A - D;
            }
            count++;
        }

        if (A>0) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
}
