#!/bin/bash

read A B C D

AC=$(echo "sqrt($((A-C))^2)" | bc);
AB=$(echo "sqrt($((A-B))^2)" | bc);
BC=$(echo "sqrt($((B-C))^2)" | bc);

[ $AC -le $D -o $AB -le $D -a $BC -le $D ] && ANS="Yes" || ANS="No"
echo $ANS