#include<stdio.h>
int main()
{
    int a,b,c,d,aa,bb;
    scanf("%d %d %d %d",&a,&b,&c,&d);
    aa=d-b;
    bb=a-c;
    if(aa<=bb)
    {
        printf("Yes\n");
    }
    else{
        printf("No\n");
    }
    return 0;
}
