class DoublingLCA:
    def __init__(self,n,adj,root=0):
        self.ancestor,self.depth = [[-1]*(n+1)],[-1]*n
        stack = [(root,-1,0)]
        while stack:
            v,p,dep = stack.pop()
            self.ancestor[0][v],self.depth[v] = p,dep
            for c in adj[v]:
                if c!=p: stack.append((c,v,dep+1))
        for _ in range(max(self.depth).bit_length()-1):
            self.ancestor.append([self.ancestor[-1][v] for v in self.ancestor[-1]])
    def get_kth_ancestor(self,v,k):
        for i in range(k.bit_length()):
            if k>>i&1: v = self.ancestor[i][v]
        return v
    def get_lca(self,u,v):
        depu,depv = self.depth[u],self.depth[v]
        if depu>depv: u,v,depu,depv = v,u,depv,depu
        v = self.get_kth_ancestor(v,depv-depu)
        if u==v: return u
        for k in range(depu.bit_length()-1,-1,-1):
            nu,nv = self.ancestor[k][u],self.ancestor[k][v]
            if nu!=nv: u,v = nu,nv
        return self.ancestor[0][u]
from collections import deque
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)
lca = DoublingLCA(n,adj)
dq = deque([0]); topo = []; par = [-1]*n
while dq:
    p = dq.popleft(); topo.append(p)
    for c in adj[p]:
        if c!=par[p]: dq.append(c); par[c] = p
dp = [1]*n
for v in topo[::-1]:
    for c in adj[v]:
        if c!=par[v]: dp[v] += dp[c]
for _ in range(q):
    s,t = map(int,input().split()); s -= 1; t -= 1
    x = lca.depth[s]; y = lca.depth[t]
    if x<y: s,t,x,y = t,s,y,x
    d = x+y-2*lca.depth[lca.get_lca(s,t)]
    a = lca.get_kth_ancestor(s,d//2)
    b = lca.get_kth_ancestor(s,d//2-1)
    c = lca.get_kth_ancestor(t,d//2-1)
    if d%2: print(0)
    elif x!=y: print(dp[a]-dp[b])
    else: print(n-dp[b]-dp[c])