#include<bits/stdc++.h>
#include<atcoder/all>
#define rep(i,b) for(int i=0;i<b;i++)
#define rrep(i,b) for(int i=b-1;i>=0;i--)
#define rep1(i,b) for(int i=1;i<b;i++)
#define repx(i,x,b) for(int i=x;i<b;i++)
#define rrepx(i,x,b) for(int i=b-1;i>=x;i--)
#define fore(i,a) for(auto& i:a)
#define rng(x) (x).begin(), (x).end()
#define rrng(x) (x).rbegin(), (x).rend()
#define sz(x) ((int)(x).size())
#define pb push_back
#define fi first
#define se second
#define pcnt __builtin_popcountll

using namespace std;
using namespace atcoder;

using ll = long long;
using ld = long double;
template<typename T> using mpq = priority_queue<T, vector<T>, greater<T>>;
template<typename T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<typename T> bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
template<typename T> ll sumv(const vector<T>&a){ll res(0);for(auto&&x:a)res+=x;return res;}
bool yn(bool a) { if(a) {cout << "Yes" << endl; return true;} else {cout << "No" << endl; return false;}}
#define dame { cout << "No" << endl; return;}
#define dame1 { cout << -1 << endl; return;}
#define cout2(x,y) cout << x << " " << y << endl;
#define coutp(p) cout << p.fi << " " << p.se << endl;
#define out cout << ans << endl;
#define outd cout << fixed << setprecision(20) << ans << endl;
#define outm cout << ans.val() << endl;
#define outv fore(yans , ans) cout << yans << "\n";
#define outdv fore(yans , ans) cout << yans.val() << "\n";
#define coutv(v) {fore(vy , v) {cout << vy << " ";} cout << endl;}
#define coutv2(v) fore(vy , v) cout << vy << "\n";
#define coutvm(v) {fore(vy , v) {cout << vy.val() << " ";} cout << endl;}
#define coutvm2(v) fore(vy , v) cout << vy.val() << "\n";
using pll = pair<ll,ll>;using pil = pair<int,ll>;using pli = pair<ll,int>;using pii = pair<int,int>;using pdd = pair<ld,ld>;
using vi = vector<int>;using vd = vector<ld>;using vl = vector<ll>;using vs = vector<string>;using vb = vector<bool>;
using vpii = vector<pii>;using vpli = vector<pli>;using vpll = vector<pll>;using vpil = vector<pil>;
using vvi = vector<vector<int>>;using vvl = vector<vector<ll>>;using vvs = vector<vector<string>>;using vvb = vector<vector<bool>>;
using vvpii = vector<vector<pii>>;using vvpli = vector<vector<pli>>;using vvpll = vector<vpll>;using vvpil = vector<vpil>;
using mint = modint998244353;
//using mint = modint1000000007;
//using mint = dynamic_modint<0>;
using vm = vector<mint>;
using vvm = vector<vector<mint>>;
vector<int> dx={1,0,-1,0,1,1,-1,-1},dy={0,1,0,-1,1,-1,1,-1};
ll gcd(ll a, ll b) { return a?gcd(b%a,a):b;}
ll lcm(ll a, ll b) { return a/gcd(a,b)*b;}
#define yes {cout <<"Yes"<<endl;}
#define yesr { cout <<"Yes"<<endl; return;}
#define no {cout <<"No"<<endl;}
#define nor { cout <<"No"<<endl; return;}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#ifdef MY_LOCAL_DEBUG
#define show(x) cerr<<#x<<" = "<<x<<endl
#define showp(p) cerr<<#p<<" = "<<p.fi<<" : "<<p.se<<endl
#define show2(x,y) cerr<<#x<<" = "<<x<<" : "<<#y<<" = "<<y<<endl
#define show3(x,y,z) cerr<<#x<<" = "<<x<<" : "<<#y<<" = "<<y<<" : "<<#z<<" = "<<z<<endl
#define show4(x,y,z,x2) cerr<<#x<<" = "<<x<<" : "<<#y<<" = "<<y<<" : "<<#z<<" = "<<z<<" : "<<#x2<<" = "<<x2<<endl
#define test(x) cout << "test" << x << endl
#define showv(v) {fore(vy , v) {cout << vy << " ";} cout << endl;}
#define showv2(v) fore(vy , v) cout << vy << "\n";
#define showvm(v) {fore(vy , v) {cout << vy.val() << " ";} cout << endl;}
#define showvm2(v) fore(vy , v) cout << vy.val() << "\n";
#else
#define show(x)
#define showp(p)
#define show2(x,y)
#define show3(x,y,z)
#define show4(x,y,z,x2)
#define test(x)
#define showv(v)
#define showv2(v)
#define showvm(v)
#define showvm2(v)
#endif

template<typename T>
struct LCA {
	int n, root, l;
	vector<vector<int>> to;
	vector<vector<T>> co;
	vector<int> dep;
	vector<T> costs;
	vector<vector<int>> par;
	LCA(int n):n(n),to(n),co(n),dep(n),costs(n) {
		l = 0;
		while ((1<<l) < n) ++l;
		par = vector<vector<int>>(n+1,vector<int>(l,n));
	}
	void add_edge(int a, int b, T c=1) {
		to[a].push_back(b); co[a].push_back(c);
		to[b].push_back(a); co[b].push_back(c);
	}

	// par[x][0],dep,costsを計算
	void _dfs(int v, int d=0, T c=0, int p=-1) {
		if (p != -1) par[v][0] = p;
		dep[v] = d;
		costs[v] = c;
		for (int i = 0; i < sz(to[v]); ++i) {
			int u = to[v][i];
			if (u == p) continue;
			_dfs(u, d+1, c+co[v][i], v);
		}
	}

	void init(int _root=0) {
		root = _root;
		_dfs(root);
		for (int i = 0; i < l-1; ++i) {
			for (int v = 0; v < n; ++v) {
				par[v][i+1] = par[par[v][i]][i];
			}
		}
	}
	int lca(int a,int b){
		if (dep[a] > dep[b]) swap(a,b);
		int gap = dep[b]-dep[a];
		for (int i = l-1; i >= 0; --i) {
			int len = 1<<i;
			if (gap >= len) {
				gap -= len;
				b = par[b][i];
			}
		}
		if (a == b) return a;
		for (int i = l-1; i >= 0; --i) {
			int na = par[a][i];
			int nb = par[b][i];
			if (na != nb) a = na, b = nb;
		}
		return par[a][0];
	}

	int getPar(int x,int k){
		int now = x;
		rrep(i,30){
			if ((k >> i & 1) == 1){
				now = par[now][i];
			}
		}
		return now;
	}
	int length(int a, int b) {
		int c = lca(a,b);
		return dep[a]+dep[b]-dep[c]*2;
	}
	T dist(int a, int b) {
		int c = lca(a,b);
		return costs[a]+costs[b]-costs[c]*2;
	}
};

// 初期化方法 LCA<T> g(n) : nは頂点数、Tはコストのタイプ、注) 宣言 → add_edge → init の順で呼び出す 
// add_edge(a,b,c) : a,b間にコストcの辺をはる。cは省略可(1となる)。
// init() : ダブリングにより各頂点の2^i個上の親を計算。結果はpar[v][i]に入る。
// lca(a,b) : 頂点a,bのlcaを出力。
// getPar(x,k) : 頂点xの2^k上の祖先を出力。
// length(a,b) : 頂点a,b間の辺の数を出力。
// dist(a,b) : 頂点a,b間のコストを出力。

void solve(){
	int n,q; cin>>n>>q;
	vvi e(n);
	LCA<int> l(n);
	rep(i,n-1){
		int a,b; cin>>a>>b;
		a--; b--;
		e[a].pb(b);
		e[b].pb(a);
		l.add_edge(a,b);
	}
	l.init();
	// vvi q_center(n);
	vvpii q_ver(n);
	vl ans(q,n);

	rep(i,q){
		int s,t; cin>>s>>t;
		s--; t--;
		int x;
		ll d = l.dist(s,t);
		if (d%2==1){
			ans[i] = 0;
			continue;
		}
		d /= 2;
		if (l.dep[s]>l.dep[t]){
			x = l.getPar(s,d);
		}else{
			x = l.getPar(t,d);
		}
		q_ver[s].pb({i,x});
		q_ver[t].pb({i,x});
		// q_center[x].pb(i);
	}

	vvi query(n);

	auto dfs = [&](auto dfs,int x,int pre)->int{
		int sum = 0;
		vi sub = query[x];
		query[x].clear();
		fore(y , q_ver[x]){
			query[y.se].pb(y.fi);
		}
		fore(y , e[x]){
			if(y == pre) continue;
			int r = dfs(dfs ,y ,x);
			sum += r;
			fore(y , query[x]){
				ans[y] -= r;
			}
			query[x].clear();
		}
		sum++;
		fore(y , sub){
			ans[y] -= (n-sum);
		}
		return sum;
	};
	dfs(dfs,0,-1);
	outv;

	return;
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);

	int t = 1;
	//cin>>t;

	rep(i,t){
		solve();
	}

	return 0;
}