"use strict";
function Main(input) {
    let nums = input.split(/\s/).map((v) => v - 0);
    const N = nums[0];
    const K = nums[1];

    let t = (N + 1) / 2;

    console.log(t >= K ? "Yes" : "No");
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));
