// #include "atcoder/convolution"
#include "atcoder/dsu"
#include "atcoder/fenwicktree"
#include "atcoder/lazysegtree"
#include "atcoder/math"
#include "atcoder/maxflow"
#include "atcoder/mincostflow"
#include "atcoder/modint"
#include "atcoder/scc"
#include "atcoder/segtree"
#include "atcoder/string"
#include "atcoder/twosat"
using namespace atcoder;
#include <bits/stdc++.h>
using namespace std;
// #include <boost/multiprecision/cpp_int.hpp>
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep2(i,a,b) for (int i = (int)(a); i < (int)(b); i++)
#define all(v) v.begin(),v.end()
#define inc(x,l,r) ((l)<=(x)&&(x)<(r)) 
#define Unique(x) sort(all(x)), x.erase(unique(all(x)), x.end())
#define pcnt __builtin_popcountll
typedef long long ll;
#define int ll
using ld = long double;
using vi = vector<int>;
using vs = vector<string>;
using P = pair<int,int>;
using vp = vector<P>;
// using Bint = boost::multiprecision::cpp_int;
template<typename T1,typename T2> bool chmax(T1 &a, const T2 b) {if (a < b) {a = b; return true;} else return false; }
template<typename T1,typename T2> bool chmin(T1 &a, const T2 b) {if (a > b) {a = b; return true;} else return false; }
template<typename T> using priority_queue_greater = priority_queue<T, vector<T>, greater<T>>;
template<typename T> istream &operator>>(istream& is,vector<T> &v){for(T &in:v)is>>in;return is;}
template<typename T1,typename T2> ostream &operator<< (ostream &os, const pair<T1,T2> &p){os << p.first <<" "<<p.second;return os;}
ostream &operator<< (ostream &os, const modint1000000007 &m){os << m.val();return os;}
istream &operator>> (istream &is, modint1000000007 &m){ll in;is>>in;m=in;return is;}
ostream &operator<< (ostream &os, const modint998244353 &m){os << m.val();return os;}
istream &operator>> (istream &is, modint998244353 &m){ll in;is>>in;m=in;return is;}
template<class... T> void input(T&... a){(cin>> ... >> a);}
#ifdef LOCAL
template<typename T> ostream &operator<<(ostream &os,const vector<T> &v){os<<"\x1b[32m";rep(i,v.size())os<<v[i]<<(i+1!=v.size()?" ":"");os<<"\x1b[0m";return os;}
template<class T> void print(T& a){cout << "\x1b[32m"<< a<< '\n' << "\x1b[0m";}
template<class T,class... Ts> void print(const T&a, const Ts&... b){cout << "\x1b[32m" << a;(cout<<...<<(cout<<' ',b));cout<<'\n' << "\x1b[0m";}
#else
template<typename T> ostream &operator<<(ostream &os,const vector<T> &v){rep(i,v.size())os<<v[i]<<(i+1!=v.size()?" ":"");return os;}
template<class T> void print(T& a){cout << a<< '\n';}
template<class T,class... Ts> void print(const T&a, const Ts&... b){cout << a;(cout<<...<<(cout<<' ',b));cout<<'\n';}
#endif
#define VI(v,n) vi v(n); input(v)
#define INT(...) int __VA_ARGS__; input(__VA_ARGS__)
#define STR(...) string __VA_ARGS__; input(__VA_ARGS__)
#define CHAR(...) char __VA_ARGS__; input(__VA_ARGS__)
int sign(ll x){return x>0?1:x<0?-1:0;}
ll ceil(ll x,ll y){assert(y!=0);if(sign(x)==sign(y))return (x+y-1)/y;return -((-x/y));}
ll floor(ll x,ll y){assert(y!=0);if(sign(x)==sign(y))return x/y;if(y<0)x*=-1,y*=-1;return x/y-(x%y<0);}
ll abs(ll x,ll y){return abs(x-y);}
ll bit(int n){return 1ll<<n;}
bool ins(string s,string t){return s.find(t)!=string::npos;}
P operator+ (const P &p, const P &q){ return P{p.first+q.first,p.second+q.second};}
P operator- (const P &p, const P &q){ return P{p.first-q.first,p.second-q.second};}
void yesno(bool ok,string y="Yes",string n="No"){ cout<<(ok?y:n)<<endl;}
void YESNO(bool ok,string y="YES",string n="NO"){ cout<<(ok?y:n)<<endl;}
int di[]={-1,0,1,0,-1,-1,1,1};
int dj[]={0,1,0,-1,-1,1,-1,1};
const ll INF = 8e18;
//using mint = modint1000000007;
//using mint = modint998244353;
//mint stom(const string &s,int b=10){mint res = 0;for(auto c:s)res *= b,res += c-'0';return res;}
template<bool edge>
struct HLD {
    int N;
    vector<int> roots;
    vector<vector<int>> G;
    vector<int> parent,depth,sz,in,out,head,rev,subtree_size;
    int t = 0;
    HLD() {}
    HLD(int n, vector<int> r = {0}) : N(n), roots(r),G(N),parent(N),depth(N),sz(N),in(N),out(N),head(N),rev(N),subtree_size(N,1){}

    void add_edge(int u, int v) {
        assert(0 <= u && u < N);
        assert(0 <= v && v < N);
        G[u].push_back(v);
        G[v].push_back(u);
    }

    void dfs_sz(int u, int p, int d) {
        parent[u] = p;
        depth[u] = d;
        sz[u] = 1;
        if (G[u].size() && G[u][0] == p) swap(G[u][0], G[u].back());
        for (int& v : G[u]) if (v != p) {
            dfs_sz(v, u, d + 1);
            sz[u] += sz[v];
            if (sz[G[u][0]] < sz[v]) swap(G[u][0], v);
        }
    }

    void dfs_hld(int u, int p) {
        in[u] = t++;
        rev[in[u]] = u;
        for (const int& v : G[u]) if (v != p) {
            head[v] = (v == G[u][0] ? head[u] : v);
            dfs_hld(v, u);
        }
        out[u] = t;
    }

    void dfs_subtree_size(int u, int p) {
        for(int v : G[u]) if(v != p) {
            dfs_subtree_size(v, u);
            subtree_size[u] += subtree_size[v];
        }
    }

    void build() {
        for(auto r:roots){
            head[r] = r;
            dfs_sz(r, -1, 0);
            dfs_hld(r, -1);
            dfs_subtree_size(r, -1);
        }
    }

    int la(int u, int d) const {
        assert(0 <= u && u < N);
        if(depth[u]-d < 0)return -1;
        while (true) {
            int v = head[u];
            if (in[u] - d >= in[v]) return rev[in[u] - d];
            d -= in[u] - in[v] + 1;
            u = parent[v];
        }
    }

    int lca(int u, int v) const {
        assert(0 <= u && u < N);
        assert(0 <= v && v < N);
        while (true) {
            if (in[u] > in[v]) swap(u, v);
            if (head[u] == head[v]) return u;
            v = parent[head[v]];
        }
    }

    int distance(int u, int v) const {
        assert(0 <= u && u < N);
        assert(0 <= v && v < N);
        return depth[u] + depth[v] - 2*depth[lca(u, v)];
    }

    bool on_path(int u, int v, int w) const {
        assert(0 <= u && u < N);
        assert(0 <= v && v < N);
        assert(0 <= w && w < N);
        return distance(u, w) + distance(w, v) == distance(u, v);
    }

    vector<pair<int,int>> query(int u,int v){
        assert(0 <= u && u < N);
        assert(0 <= v && v < N);
        vector<pair<int,int>> res;
        while(true){
            if(in[u]>in[v])swap(u,v);
            if(head[u]==head[v])break;
            res.emplace_back(in[head[v]],in[v]+1);
            v = parent[head[v]];
        }
        
        res.emplace_back(in[u]+edge,in[v]+1);
        return res;
    }

    pair<int,int> subtree_query(int u){
        assert(0 <= u && u < N);
        return {in[u]+edge,out[u]};
    }
};
signed main() {
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(20);

    INT(n,q);
    HLD<false> g(n);
    rep(i,n-1){
        INT(a,b);
        --a;--b;
        g.add_edge(a,b);
    }
    g.build();
    while(q--){
        INT(s,t);
        --s;--t;
        if(g.depth[s]>g.depth[t])swap(s,t);
        if(g.distance(s,t)&1)print(0);
        else{
            int l = g.lca(s,t);
            int ds = g.distance(s,l);
            int dt = g.distance(t,l);
            if(ds==dt){
                s = g.la(s,ds-1);
                t = g.la(t,dt-1);
                print(n-g.subtree_size[s]-g.subtree_size[t]);
            }
            else{
                int d = g.distance(s,t);
                int m = g.la(t,d/2);
                t = g.la(t,d/2-1);
                print(g.subtree_size[m]-g.subtree_size[t]);
            }
        }
    }
    return 0;
}