#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <climits>
#include <cstring>
#include <string>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <vector>
#include <list>
#define rep(i,m,n) for(i=m;i<=n;i++)
#define rsp(it,s) for(set<int>::iterator it=s.begin();it!=s.end();it++)
#define mod 1000000007
#define inf 0x3f3f3f3f
#define vi vector<int>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ll long long
#define pi acos(-1.0)
#define pii pair<int,int>
#define Lson L, mid, ls[rt]
#define Rson mid+1, R, rs[rt]
const int maxn=1e6+10;
using namespace std;
ll gcd(ll p,ll q){return q==0?p:gcd(q,p%q);}
ll qpow(ll p,ll q){ll f=1;while(q){if(q&1)f=f*p;p=p*p;q>>=1;}return f;}
inline ll read()
{
    ll x=0;int f=1;char ch=getchar();
    while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
    while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
    return x*f;
}
int n,m,k,t,q,tot,h[maxn],bel[maxn],fa[maxn],son[maxn],sec_son[maxn],dp[maxn],dp1[maxn],ans;
struct node
{
    int to,nxt;
}e[maxn<<1];
void add(int x,int y)
{
    tot++;
    e[tot].to=y;
    e[tot].nxt=h[x];
    h[x]=tot;
}
void dfs(int now,int pre)
{
    son[now]=sec_son[now]=inf;
    for(int i=h[now];i;i=e[i].nxt)
    {
        int to=e[i].to;
        if(to!=pre)
        {
            fa[to]=now;
            if(now!=1)bel[to]=bel[now];
            dfs(to,now);
            if(son[now]>min(son[to],to))
            {
                sec_son[now]=son[now];
                son[now]=min(son[to],to);
            }
        }
    }
}
void dfs1(int now,int pre)
{
    if(now!=1)dp1[now]=min(dp1[fa[now]],dp[now]);
    else dp1[now]=inf;
    for(int i=h[now];i;i=e[i].nxt)
    {
        int to=e[i].to;
        if(to!=pre)
        {
            dfs1(to,now);
        }
    }
}
void solve(int x,int y)
{
    int now_ans=inf;
    for(int i=h[1];i;i=e[i].nxt)
    {
        int to=e[i].to;
        if(to!=bel[x]&&to!=bel[y])now_ans=min(min(now_ans,son[to]),to);
    }
    if(x!=1)now_ans=min(now_ans,son[x]);
    if(y!=1)now_ans=min(now_ans,son[y]);
    now_ans=min(now_ans,dp1[x]);
    now_ans=min(now_ans,dp1[y]);
    ans=now_ans;
}
int main()
{
    int i,j;
    while(~scanf("%d%d",&n,&q))
    {
        ans=0;
        tot=0;
        memset(h,0,sizeof(h));
        rep(i,1,n)bel[i]=i;
        rep(i,1,n-1)
        {
            int a,b;
            scanf("%d%d",&a,&b);
            add(a,b);
            add(b,a);
        }
        dfs(1,0);
        rep(i,2,n)
        {
            if(fa[i]==1)
            {
                dp[i]=inf;
                continue;
            }
            if(min(son[i],i)!=son[fa[i]])dp[i]=son[fa[i]];
            else dp[i]=sec_son[fa[i]];
        }
        dfs1(1,0);
        while(q--)
        {
            int a,b;
            scanf("%d%d",&a,&b);
            a^=ans,b^=ans;
            if(bel[a]==bel[b])ans=1;
            else solve(a,b);
            printf("%d\n",ans);
        }
    }
    //system("Pause");
    return 0;
}