import sys
input = sys.stdin.readline
sys.setrecursionlimit(500000)
n,q=map(int,input().split())
adj=[[] for _ in range(n)]
for _ in range(n-1):
  a,b=map(int,input().split())
  adj[a-1].append(b-1)
  adj[b-1].append(a-1)
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)
class HLD:
    def __init__(self, g):
        self.g = g
        self.n = len(g)
        self.parent = [-1]*self.n
        self.size = [1]*self.n
        self.head = [0]*self.n
        self.preorder = [0]*self.n
        self.k = 0
 
        for v in range(self.n):
            if self.parent[v] == -1:
                self.dfs_pre(v)
                self.dfs_hld(v)
 
    def dfs_pre(self, v):
        g = self.g
        stack = [v]
        order = [v]
        while stack:
            v = stack.pop()
            for u in g[v]:
                if self.parent[v] == u:
                    continue
                self.parent[u] = v
                stack.append(u)
                order.append(u)
 
        # 隣接リストの左端: heavyな頂点への辺
        # 隣接リストの右端: 親への辺
        while order:
            v = order.pop()
            child_v = g[v]
            if len(child_v) and child_v[0] == self.parent[v]:
                child_v[0], child_v[-1] = child_v[-1], child_v[0]
            for i, u in enumerate(child_v):
                if u == self.parent[v]:
                    continue
                self.size[v] += self.size[u]
                if self.size[u] > self.size[child_v[0]]:
                    child_v[i], child_v[0] = child_v[0], child_v[i]
 
    def dfs_hld(self, v):
        stack = [v]
        while stack:
            v = stack.pop()
            self.preorder[v] = self.k
            self.k += 1
            top = self.g[v][0]
            # 隣接リストを逆順に見ていく（親 > lightな頂点への辺 > heavyな頂点 (top)）
            # 連結成分が連続するようにならべる
            for u in reversed(self.g[v]):
                if u == self.parent[v]:
                    continue
                if u == top:
                    self.head[u] = self.head[v]
                else:
                    self.head[u] = u
                stack.append(u)
 
    def for_each(self, u, v):
        # [u, v]上の頂点集合の区間を列挙
        while True:
            if self.preorder[u] > self.preorder[v]:
                u, v = v, u
            l = max(self.preorder[self.head[v]], self.preorder[u])
            r = self.preorder[v]
            yield l, r # [l, r]
            if self.head[u] != self.head[v]:
                v = self.parent[self.head[v]]
            else:
                return
 
    def for_each_edge(self, u, v):
        # [u, v]上の辺集合の区間列挙
        # 辺の情報は子の頂点に
        while True:
            if self.preorder[u] > self.preorder[v]:
                u, v = v, u
            if self.head[u] != self.head[v]:
                yield self.preorder[self.head[v]], self.preorder[v]
                v = self.parent[self.head[v]]
            else:
                if u != v:
                    yield self.preorder[u]+1, self.preorder[v]
                break
 
    def subtree(self, v):
        # 頂点vの部分木の頂点集合の区間 [l, r)
        l = self.preorder[v]
        r = self.preorder[v]+self.size[v]
        return l, r
 
    def lca(self, u, v):
        # 頂点u, vのLCA
        while True:
            if self.preorder[u] > self.preorder[v]:
                u, v = v, u
            if self.head[u] == self.head[v]:
                return u
            v = self.parent[self.head[v]]
hld = HLD(adj)
for _ in range(q):
  s,t=map(int,input().split())
  s-=1
  t-=1
  x=hld.lca(s,t)
  d=depth[s]+depth[t]-2*depth[x]
  if d%2==1:
    print(0)
    continue
  if depth[s]-depth[x]==d//2:
    print(n-size[x]+1)
  else:
    print(size[x])