#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001

struct lca{
	
	vector<int> depth;
	vector<vector<int>> parents;
	
	int max_j=18;
	
	lca(int n,vector<vector<int>> &E){
		rep(i,100){
			if((1<<i)>E.size()){
				max_j = i;
				break;
			}
		}
		depth.assign(E.size(),-1);
		parents.assign(E.size(),vector<int>(max_j,-1));
		
		
		
		stack<int> s;
		s.push(n);
		depth[n] = 0;
		while(s.size()!=0){
			int k = s.top();
			s.pop();
			for(int i=0;i<E[k].size();i++){
				int x = E[k][i];
				if(depth[x]!=-1)continue;
				s.push(x);
				depth[x] = depth[k]+1;
				for(int j=0;j<max_j;j++){
					if(j==0){
						parents[x][j] = k;
					}
					else{
						parents[x][j] = parents[parents[x][j-1]][j-1];
					}
					if(parents[x][j] == -1)break;
				}
			}
		}
	}
	
	
	int kth_parent(int u,int k){
		for(int i=0;i<max_j;i++){
			if(k==0)break;
			if(u==-1)break;
			if(k%2){
				u = parents[u][i];
			}
			k/=2;
		}
		return u;
	}
	
	int query(int u,int v){
		if(depth[u]<depth[v])swap(u,v);
		u = kth_parent(u,depth[u]-depth[v]);
		
		if(u==v){
			return u;
		}
		
		for(int i=max_j-1;i>=0;i--){
			if(parents[u][i]!=parents[v][i]){
				u = parents[u][i];
				v = parents[v][i];
			}
		}
		
		return parents[u][0];
		
	}
	
	int get_distance(int u,int v){
		return depth[u]+depth[v]-2*depth[query(u,v)];
	}
	
	
};

vector<int> sz;

void dfs(int cv,int pv,vector<vector<int>> &E){
	sz[cv] = 1;
	rep(i,E[cv].size()){
		int to = E[cv][i];
		if(to==pv)continue;
		dfs(to,cv,E);
		sz[cv] += sz[to];
	}
}

int main(){
	
	int n,q;
	cin>>n>>q;
	vector<vector<int>> E(n);
	rep(i,n-1){
		int a,b;
		cin>>a>>b;
		a--,b--;
		E[a].push_back(b);
		E[b].push_back(a);
	}
	lca L(0,E);
	sz.resize(n);
	dfs(0,-1,E);
	rep(_,q){
		int a,b;
		cin>>a>>b;
		a--,b--;
		int d =L.get_distance(a,b);
		if(d%2==1){
			cout<<0<<endl;
			continue;
		}
		if(L.depth[a]<L.depth[b])swap(a,b);
		int c = L.kth_parent(a,d/2);
		if(L.query(a,b)!=c){
			cout<<sz[c] - sz[L.kth_parent(a,d/2 - 1)]<<endl;
		}
		else{
			cout<<n - sz[L.kth_parent(a,d/2-1)] - sz[L.kth_parent(b,d/2-1)]<<endl; 
		}
	}
	
	return 0;
}