Vasya goes to visit his classmate Petya. Vasya knows that Petya's apartment number is n. 

There is only one entrance in Petya's house and the distribution of apartments is the following: the first floor contains 2 apartments, every other floor contains x apartments each. Apartments are numbered starting from one, from the first floor. I.e. apartments on the first floor have numbers 1 and 2, apartments on the second floor have numbers from 3 to (x + 2), apartments on the third floor have numbers from (x + 3) to (2 ⋅ x + 2), and so on.

Your task is to find the number of floor on which Petya lives. Assume that the house is always high enough to fit at least n apartments.

You have to answer t independent test cases.

Input

The first line of the input contains one integer t (1 ≤ t ≤ 1000) — the number of test cases. Then t test cases follow.

The only line of the test case contains two integers n and x (1 ≤ n, x ≤ 1000) — the number of Petya's apartment and the number of apartments on each floor of the house except the first one (there are two apartments on the first floor).

Output

For each test case, print the answer: the number of floor on which Petya lives.

Example

Input


4
7 3
1 5
22 5
987 13


Output


3
1
5
77

Note

Consider the first test case of the example: the first floor contains apartments with numbers 1 and 2, the second one contains apartments with numbers 3, 4 and 5, the third one contains apartments with numbers 6, 7 and 8. Therefore, Petya lives on the third floor.

In the second test case of the example, Petya lives in the apartment 1 which is on the first floor.
import heapq as hq
from heapq import heappop,heappush
from collections import deque,defaultdict,Counter
from sys import stdin,stdout


def inp():
	return int(stdin.readline())


def inlt():
	return list(map(int,stdin.readline().split()))


def insr():
	return list(stdin.readline().strip())


def invr():
	return map(int,stdin.readline().split())




def subset_sum_count(arr,n,sum):
	dp=[[0 for _ in range(sum+1)] for _ in range(n+1)]
	for i in range(n+1):
		for j in range(sum+1):
			if j==0:
				dp[i][j]=1
			elif arr[i-1]<=j:
				dp[i][j]=dp[i-1][j-arr[i-1]]+dp[i-1][j]
			else:
				dp[i][j]=dp[i-1][j]
	return dp[n][sum]


def binary_search(func,lo,hi,abs_prec=1e-7):
	""" Locate the first value x s.t. func(x) = True within [lo, hi] """
	while abs(hi-lo)>abs_prec:
		mi=lo+(hi-lo)/2
		if func(mi):
			hi=mi
		else:
			lo=mi
	
	return (lo+hi)/2


def ternary_search(func,lo,hi,abs_prec=1e-7):
	""" Find maximum of unimodal function func() within [lo, hi] """
	while abs(hi-lo)>abs_prec:
		lo_third=lo+(hi-lo)/3
		hi_third=hi-(hi-lo)/3
		
		if func(lo_third)<func(hi_third):
			lo=lo_third
		else:
			hi=hi_third
	
	return (lo+hi)/2


def discrete_binary_search(func,lo,hi):
	""" Locate the first value x s.t. func(x) = True within [lo, hi] """
	while lo<hi:
		mi=lo+(hi-lo)//2
		if func(mi):
			hi=mi
		else:
			lo=mi+1
	
	return lo


def discrete_ternary_search(func,lo,hi):
	""" Find the first maximum of unimodal function func() within [lo, hi] """
	while lo<=hi:
		lo_third=lo+(hi-lo)//3
		hi_third=lo+(hi-lo)//3+(1 if 0<hi-lo<3 else (hi-lo)//3)
		
		if func(lo_third)<func(hi_third):
			lo=lo_third+1
		else:
			hi=hi_third-1
	
	return lo
	
	return -1


def right_rotate(a,s):
	return a[s:]+a[:s]


def dec_to_bin(x):
	return int(bin(x)[2:])


def str_to_integer_list(n):
	a=[]
	for i in range(len(n)):
		a.append(int(n[i]))
	return a


def list_to_str(l):
	s=""
	for i in l:
		s+=str(i)
	return s


def dijkstra(s,N,E):
	visited=set()
	dist={}
	for i in range(1,N+1):
		dist[i]=1<<29
	queue=[(dist[i],i) for i in range(1,N+1)]
	hq.heappush(queue,(0,s))
	dist[s]=0
	while queue:
		d,u=hq.heappop(queue)
		if u in visited:
			continue
		#Relax all the neighbours of u
		for t in E[u]:
			v,r=t
			if dist[v]>d+r:
				dist[v]=d+r
				hq.heappush(queue,(dist[v],v))
		#Node u has been processed
		visited.add(u)
	return dist


def prime_sieve(n):
	"""returns a sieve of primes >= 5 and < n"""
	flag=n%6==2
	sieve=bytearray((n//3+flag>>3)+1)
	for i in range(1,int(n**0.5)//3+1):
		if not (sieve[i>>3]>>(i&7))&1:
			k=(3*i+1)|1
			for j in range(k*k//3,n//3+flag,2*k):
				sieve[j>>3]|=1<<(j&7)
			for j in range(k*(k-2*(i&1)+4)//3,n//3+flag,2*k):
				sieve[j>>3]|=1<<(j&7)
	return sieve


def prime_list(n):
	"""returns a list of primes <= n"""
	res=[]
	if n>1:
		res.append(2)
	if n>2:
		res.append(3)
	if n>4:
		sieve=prime_sieve(n+1)
		res.extend(3*i+1|1 for i in range(1,(n+1)//3+(n%6==1)) if not (sieve[i>>3]>>(i&7))&1)
	return res


def dijkstra(n,graph,start):
	""" Uses Dijkstra's algortihm to find the shortest path between in a graph. """
	dist,parents=[float("inf")]*n,[-1]*n
	dist[start]=0
	queue=[(0,start)]
	while queue:
		path_len,v=heappop(queue)
		if path_len==dist[v]:
			for w,edge_len in graph[v]:
				if edge_len+path_len<dist[w]:
					dist[w],parents[w]=edge_len+path_len,v
					heappush(queue,(edge_len+path_len,w))
	
	return dist,parents


def path(start,end,parent):
	path=[end]
	while path[-1]!=start:
		path.append(parent[path[-1]])
	path.reverse()
	return path


def bfs(graph,start,goal):
	"""
	finds a shortest path in undirected `graph` between `start` and `goal`.
	If no path is found, returns `None`
	"""
	if start==goal:
		return [start]
	visited={start}
	queue=deque([(start,[])])
	
	while queue:
		current,path=queue.popleft()
		visited.add(current)
		for neighbor in graph[current]:
			if neighbor==goal:
				return path+[current,neighbor]
			if neighbor in visited:
				continue
			queue.append((neighbor,path+[current]))
			visited.add(neighbor)
	return None  # no path found. not strictly needed


def fillPrefixSum(arr,n,prefixSum):
	prefixSum[0]=arr[0]
	
	# Adding present element
	# with previous element
	for i in range(1,n):
		prefixSum[i]=prefixSum[i-1]+arr[i]


def check(a,ind,d1):
	beg=a[:ind+1]
	end=a[ind+1:]
	d=[]
	c=0
	for i in end:
		if i-d1 in beg:
			c+=1
	return c


'''for _ in range(int(input())):
	n,m=list(map(int,input().split()))
	graph=defaultdict(list)
	distance=[-1]*(n+1)
	visited=[False]*(n+1)
	for _ in range(m):
		x,y=list(map(int,input().split()))
		graph[x].append(y)
		graph[y].append(x)'''
'''for _ in range(int(input())):
	n,m=list(map(int,input().split()))
	graph=[[]for _ in range(n+1)]
	distance=[-1]*(n+1)
	visited=[False]*(n+1)
	for _ in range(m):
		x,y,w=list(map(int,input().split()))
		graph[x].append([y,w])
		graph[y].append([x,w])'''

import os
import sys
from io import BytesIO,IOBase


def DecimalToBinary(n):
	def helper(n):
		if n==0:
			return ''  # <- empty string
		else:
			if n%2==1:
				binaryDigit='1'
			else:
				binaryDigit='0'
			return helper(n//2)+binaryDigit
	
	if n==0:
		result='0'  # <- "leading zero" only for `n == 0`
	else:
		result=helper(n)
	return result


def p(board):
	for i in range(8):
		s=""
		for j in range(8):
			s+=board[i][j]
		print(s)


def binaryToDecimal(n):
	return int(n,2)


def decimalToBinary(n):
	return bin(n).replace("0b","")


def solve(a,b):
	x=DecimalToBinary(a);
	y=DecimalToBinary(b)
	z=x+y
	l=y+x
	
	r=binaryToDecimal(z)-binaryToDecimal(l)
	return r


def mostFrequent(arr,n):
	# Sort the array
	arr.sort()
	
	# find the max frequency using
	# linear traversal
	max_count=1;
	res=arr[0];
	curr_count=1
	
	for i in range(1,n):
		if (arr[i]==arr[i-1]):
			curr_count+=1
		
		else:
			if (curr_count>max_count):
				max_count=curr_count
				res=arr[i-1]
			
			curr_count=1
	
	# If last element is most frequent
	if (curr_count>max_count):
		max_count=curr_count
		res=arr[n-1]
	
	return res


from bisect import bisect_right,bisect_left


def lds(arr,n):
	lds=[0]*n
	max=0
	
	for i in range(n):
		lds[i]=1
	
	for i in range(1,n):
		for j in range(i):
			if (arr[i]<arr[j] and
					lds[i]<lds[j]+1):
				lds[i]=lds[j]+1
	
	for i in range(n):
		if (max<lds[i]):
			max=lds[i]
	
	# returns the length of the LDS
	return max


import math


def prefix(a):
	pre=[]
	pre.append(a[0])
	for i in range(1,len(a)):
		pre.append(pre[i-1]+a[i])
	return pre
def solve(n,x,size):
	res=10000000
	if n==0:
		return 0
	if size==0:
		return 0
	for i in x:
		
		res=1+min(res,solve(n-i,x,size-1))
		return res




def main():
	for _ in range(inp()):
		n,x=invr()
		if n<3:
			print(1)
		else:
			res=math.ceil((n-2)/x)+1
			print(int(res))
		
		
				
		
			
		
			
					
			
		
		
			
			
	
		

	
	
	
	
		
		

# region fastio
BUFSIZE=8192


class FastIO(IOBase):
	newlines=0
	
	def __init__(self,file):
		self._fd=file.fileno()
		self.buffer=BytesIO()
		self.writable="x" in file.mode or "r" not in file.mode
		self.write=self.buffer.write if self.writable else None
	
	def read(self):
		while True:
			b=os.read(self._fd,max(os.fstat(self._fd).st_size,BUFSIZE))
			if not b:
				break
			ptr=self.buffer.tell()
			self.buffer.seek(0,2),self.buffer.write(b),self.buffer.seek(ptr)
		self.newlines=0
		return self.buffer.read()
	
	def readline(self):
		while self.newlines==0:
			b=os.read(self._fd,max(os.fstat(self._fd).st_size,BUFSIZE))
			self.newlines=b.count(b"\n")+(not b)
			ptr=self.buffer.tell()
			self.buffer.seek(0,2),self.buffer.write(b),self.buffer.seek(ptr)
		self.newlines-=1
		return self.buffer.readline()
	
	def flush(self):
		if self.writable:
			os.write(self._fd,self.buffer.getvalue())
			self.buffer.truncate(0),self.buffer.seek(0)


class IOWrapper(IOBase):
	def __init__(self,file):
		self.buffer=FastIO(file)
		self.flush=self.buffer.flush
		self.writable=self.buffer.writable
		self.write=lambda s:self.buffer.write(s.encode("ascii"))
		self.read=lambda:self.buffer.read().decode("ascii")
		self.readline=lambda:self.buffer.readline().decode("ascii")


sys.stdin,sys.stdout=IOWrapper(sys.stdin),IOWrapper(sys.stdout)
input=lambda:sys.stdin.readline().rstrip("\r\n")

# endregion

if __name__=="__main__":
	main()

