(let [
	numMin (volatile! 10)
	numMax (volatile! 1000000001)
]
	(loop[turn 0]
		(let [chkNum (if(= 0 turn) 100 (int(/(+ @numMin @numMax) 2)))]
			(println "?" chkNum)(flush)
			(let [chk (read-line)]
				(if(= "1" chk) (vreset! numMin chkNum)
				(when(= "-1" chk) (vreset! numMax chkNum)))
				(if(= "0" chk)(do
					(println "!" (+ chkNum turn))(flush)
				)
				(do
					(when(< 0 @numMin) (vswap! numMin dec))
					(vswap! numMax dec)
					(recur (inc turn))
				))
			)
		)
	)
)