import sys
input = sys.stdin.readline
sys.setrecursionlimit(500000)
n,q=map(int,input().split())
adj=[[] for _ in range(n)]
S=[]
for _ in range(n-1):
  a,b=map(int,input().split())
  adj[a-1].append(b-1)
  adj[b-1].append(a-1)
  S.append((a,b))
depth = [0]*n
seen = [0]*n
size=[0]*n
def dfs(v, e):
  depth[v] = e
  seen[v]=1
  tot=1
  for w in adj[v]:
    if seen[w]==0:
      tot+=dfs(w, e+1)
  size[v]=tot
  return tot
dfs(0, 0)
N=n
INF = 10 ** 16
depth = [INF] * N
dfs_seq = [INF] * N
# 0を根にして深さdepthとDFS順序dfs_seqを求める
todo = [(0, 0)]
count = 0
while todo:
    d, pos = todo.pop()
    if dfs_seq[pos] < INF:
        continue
    dfs_seq[pos] = count
    count += 1
    depth[pos] = d
    for next_ in adj[pos]:
        todo.append((d + 1, next_))
# 2 ** k 個上の頂点を前計算する（k < log2 N）
import math
K = int(math.log2(N)) + 1
up2 = [[INF] * N for _ in range(K)]
for a, b in S:
    if depth[a-1] < depth[b-1]:
        up2[0][b-1] = a-1
    else:
        up2[0][a-1] = b-1
for k in range(1, K):
    for p in range(N):
        if up2[k-1][p] < INF:
            up2[k][p] = up2[k-1][up2[k-1][p]]
        else:
            up2[k][p] = INF
# p個上の頂点をダブリングで求める（p <= depth[n]）
def up(n, p):
    k = 0
    while n > 0:
        if n % 2:
            p = up2[k][p]
            if p == INF:
                break
        n //= 2
        k += 1
    return p
# 最小共通祖先LCAを求める
def lca(p, q):
    # 深い方のdepthを、浅い方に揃える
    if depth[p] > depth[q]:
        p, q = q, p
    d = depth[p]
    q = up(depth[q] - d, q)
    # depthをそろえた頂点が同じであれば、それが答え
    if p == q:
        return p
    # さもなければ、前計算した2**k個上の頂点を順に見比べて、答えを探索する
    k = K - 1
    while k >= 0:
        p1, q1 = up2[k][p], up2[k][q]
        if p1 != q1:
            p, q = p1, q1
        else:
            ans = p1
        k -= 1
    return ans
for _ in range(q):
  s,t=map(int,input().split())
  s-=1
  t-=1
  x=lca(s,t)
  d=depth[s]+depth[t]-2*depth[x]
  if d%2==1:
    print(0)
    continue
  if x==s:
    u1=up(d//2,t)
    u2=up(d//2-1,t)
    print(size[u1]-size[u2])
  elif x==t:
    u1=up(d//2,s)
    u2=up(d//2-1,s)
    print(size[u1]-size[u2])    
  elif depth[s]-depth[x]==d//2:
    print(n-size[x]+1)
  else:
    if depth[s]>depth[t]:
      u1=up(d//2,s)
      u2=up(d//2-1,s)
      print(size[u1]-size[u2])
    else:
      u1=up(d//2,t)
      u2=up(d//2-1,t)
      print(size[u1]-size[u2])