int main(void) {
    unsigned long     a,b,c;
    int r;
    scanf( "%ld", &a );
    scanf( "%ld", &b );
    scanf( "%ld", &c );
    r = a / b;
    if ( (c * ((r + r) / 3 )) >= a ) {
        printf("YES\n");
    } else {
        printf("NO\n");
    }
	return 0;
}