function Main(input) {
    let [A,B,C,D] = input.split(" ").map(e => Number(e));
    const battle = () => {
        if (index % 2 === 0) {
            C -= B
        } else {
            A -= D
        }
        index ++
    }
    let index = 0;
    while (A > 0 && C > 0) {
        battle()
    }
    console.log(index % 2 === 1 ? "Yes" : "No")
}
// Main("46 4 40 5")
Main(require("fs").readFileSync("/dev/stdin", "utf8"));
