#include <stdio.h>

int main(){
    int a,b,c,d;
    int saude1,saude2;

    scanf("%d %d %d %d",&a,&b,&c,&d);

    if(c -b >a - d)
        printf("No\n");
    else if(c -b<=a -d)
        printf("Yes\n");






    return 0;
}
