#!/bin/bash
read A B C D

export A
export B
export C
export D

while true;
do
        # takahashi turn
        if [ $((${C}-${B})) -le 0 ]; then
                echo Yes
                break
        fi
        C=`echo $((${C}-${B}))`

        # aoki turn
        if [ $((${A}-${D})) -le 0 ]; then
                echo No
                break
        fi
        A=`echo $((${A}-${D}))`

done