import sys
input = sys.stdin.readline

N,Q=map(int,input().split())

E=[[] for i in range(N)]

for i in range(N-1):
    a,b=map(int,input().split())
    a-=1
    b-=1

    E[a].append(b)
    E[b].append(a)

ROOT=0

QUE=[ROOT]
DEPTH=[0]*N
DEPTH[ROOT]=0

Parent=[-1]*N
Parent[ROOT]=N # ROOTの親を定めておく.
Child=[[] for i in range(N)]
TOP_SORT=[] # トポロジカルソート

while QUE: # トポロジカルソートと同時に親を見つける
    x=QUE.pop()
    TOP_SORT.append(x)
    for to in E[x]:
        if Parent[to]==-1:
            Parent[to]=x
            Child[x].append(to)
            QUE.append(to)
            DEPTH[to]=DEPTH[x]+1

Children=[1]*N

for x in TOP_SORT[::-1]: #（自分を含む）子ノードの数を調べる
    if x==ROOT:
        break
    Children[Parent[x]]+=Children[x]

DOUBLING=[[-1]*N for b in range(30)]

for i in range(N):
    if i!=ROOT:
        DOUBLING[0][i]=Parent[i]

for b in range(1,30):
    for i in range(N):
        if DOUBLING[b-1][i]!=-1:
            DOUBLING[b][i]=DOUBLING[b-1][DOUBLING[b-1][i]]

# 頂点aの先祖で深さdの頂点を探す
def search_depth(a,d):
    now=a

    for b in range(30,-1,-1):
        if (DEPTH[a]-d) & (1<<b) != 0:
            now=DOUBLING[b][now]

    return now

def lca(x,y):
    if DEPTH[x]<DEPTH[y]:
        y=search_depth(y,DEPTH[x])
    elif DEPTH[x]>DEPTH[y]:
        x=search_depth(x,DEPTH[y])

    if x==y:
        return x

    for b in range(29,-1,-1):
        if DOUBLING[b][x]!=DOUBLING[b][y]:
            x=DOUBLING[b][x]
            y=DOUBLING[b][y]

    if Parent[x]==Parent[y]:
        return Parent[x]

for tests in range(Q):
    a,b=map(int,input().split())
    a-=1
    b-=1

    if DEPTH[a]>DEPTH[b]:
        a,b=b,a

    LCA=lca(a,b)

    if LCA==a:
        dis=DEPTH[b]-DEPTH[a]

        if dis%2==1:
            print(0)
            continue
        else:
            x=search_depth(b,DEPTH[b]-dis//2)
            y=search_depth(b,DEPTH[b]-dis//2+1)
            print(Children[x]-Children[y])
    else:
        dis1=DEPTH[a]-DEPTH[LCA]
        dis2=DEPTH[b]-DEPTH[LCA]

        if (dis1+dis2)%2==1:
            print(0)
            continue
        else:
            if dis1==dis2:
                print(N-Children[LCA]+1)
            elif dis1>dis2:
                x=search_depth(a,DEPTH[a]-(dis1+dis2)//2)
                y=search_depth(a,DEPTH[a]-(dis1+dis2)//2+1)
                print(Children[x]-Children[y])
            else:
                x=search_depth(b,DEPTH[b]-(dis1+dis2)//2)
                y=search_depth(b,DEPTH[b]-(dis1+dis2)//2+1)
                print(Children[x]-Children[y])