BC ROUND 43# 03 HDU 5266

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#pragma comment(linker, "/STACK:102400000,102400000")
using namespace std;

const int N=300015;

struct Edge{
    int u,v,next;
}edge[N*2];
int head[N],tot,dtot;
int dp[N*2][20];
int ver[2*N],R[2*N],first[N],dir[N];
bool vis[N];
int ans;
int tag[N*4];

void addedge(int u,int v){
    edge[tot].u=u;
    edge[tot].v=v;
    edge[tot].next=head[u];
    head[u]=tot++;
}

void dfs(int u ,int dep) {  
    vis[u] = true; ver[++dtot] = u; first[u] = dtot; R[dtot] = dep;  
    for(int k=head[u]; k!=-1; k=edge[k].next)  
        if( !vis[edge[k].v] ) {  
            int v = edge[k].v ;
            dfs(v,dep+1);  
            ver[++dtot] = u; R[dtot] = dep;  
        }  
}

void ST(int n) {  
    for(int i=1;i<=n;i++)  
        dp[i][0] = i;  
    for(int j=1;(1<<j)<=n;j++) {  
        for(int i=1;i+(1<<j)-1<=n;i++) {  
            int a = dp[i][j-1] , b = dp[i+(1<<(j-1))][j-1];  
            dp[i][j] = R[a]<R[b]?a:b;  
        }  
    }  
}

int RMQ(int l,int r)  {  
    int k=0;  
    while((1<<(k+1))<=r-l+1)  
        k++;  
    int a = dp[l][k], b = dp[r-(1<<k)+1][k]; 
    return R[a]<R[b]?a:b;  
}

int LCA(int u ,int v)  {  
    int x = first[u] , y = first[v];  
    if(x > y) swap(x,y);  
    int res = RMQ(x,y);  
    return ver[res];  
}

void query(int rt,int l,int r,int L,int R){
//    cout<<L<<" "<<R<<endl;
    if(tag[rt]!=-1&&l<=L&&R<=r){
        if(ans==-1) ans=tag[rt];
        else {
            ans=LCA(ans,tag[rt]);
        }
        return ;
    }
    else if(L==R){
    //    cout<<L<<" "<<ans<<endl;
        tag[rt]=L;
        if(ans==-1)
            ans=L;
        else{
            ans=LCA(ans,L);
        }
        return ;
    }
    int m=(L+R)>>1;
    if(r<=m){
        query(rt<<1,l,r,L,m);
    }
    else if(l>=m+1){
        query(rt<<1|1,l,r,m+1,R);
    }
    else{
        query(rt<<1,l,r,L,m);
        query(rt<<1|1,l,r,m+1,R);
    }
    if(tag[rt<<1]!=-1&&tag[rt<<1|1]!=-1)
    tag[rt]=LCA(tag[rt<<1],tag[rt<<1|1]);
}

int main(){
    int n,q,u,v;
    while(scanf("%d",&n)!=EOF){
        memset(head,-1,sizeof(int)*(n+5));
        memset(vis,false,sizeof(bool)*(n+5));
        memset(tag,-1,sizeof(int)*(n*4));
        tot=0;
        for(int i=1;i<n;i++){
            scanf("%d%d",&u,&v);
            addedge(u,v);
            addedge(v,u);
        }
        dtot=0;
        dfs(1,1);
        ST(2*n-1);
        tag[1]=1;
        scanf("%d",&q);
    //    printf("%d",LCA(2,3));
    //    printf("%d",LCA(1,2));
    //    printf("%d",LCA(3,4));
        while(q--){
            scanf("%d%d",&u,&v);
            ans=-1;
            query(1,u,v,1,n);
            printf("%d\n",ans);
        }
    }
    return 0;
}