import std.stdio, std.conv, std.math, std.string, std.range, std.array, std.algorithm, std.typecons;

void main(){
    auto buf = readln().strip().split().map!(to!int)();
    immutable N = buf[0];
    immutable K = buf[1];

    if((N-1)/2 + 1 >= K) {
        writeln("YES");
    } else {
        writeln("NO");
    }
}
