func main()
	var q: int :: cui@input().toInt(&)
	for i(1, q)
		var ss: [][]char :: cui@input().split(" ")
		var n: int :: ss[0].toInt(&)
		var k: int :: ss[1].toInt(&)
		if(k = 1)
			do cui@print("\{n - 1}\n")
			skip i
		end if
		var ans: int :: 0
		var sum: int :: 0
		var add: int :: 1
		while loop(true)
			do sum :+ add
			if(sum >= n)
				break loop
			end if
			do add :* k
			do ans :+ 1
		end while
		do cui@print("\{ans}\n")
	end for
end func