import std; bool calc(long l, long r, long m, long k) { auto lo = k * l; auto hi = k * r; // 区間 [lo, hi] に m の倍数があるか // return lo <= hi / m * m; return (lo + m - 1) / m * m <= hi; } void main() { long l, r, m, k; scan(l, r, m, k); writeln(calc(l, r, m, k) ? "Yes" : "No"); } void scan(T...)(ref T a) { string[] ss = readln.split; foreach (i, t; T) a[i] = ss[i].to!t; } T read(T=string)() { return readln.chomp.to!T; } T[] reads(T)() { return readln.split.to!(T[]); } alias readints = reads!int;