#include <bits/stdc++.h>
#define maxx 100012
#define pp pair<ll,ll>
#define fi first
#define se second
#define ll long long
using namespace std;

const int oo=1e9;
int n,q,R,k;
vector<int> g[maxx];
int f[maxx][22],deg[maxx];
int dem=0;
int realca,dislca;

int lca(int u,int v){
    if(deg[u]<deg[v])swap(u,v);
    for(int i=20;i>=0;i--){
        if(deg[u]-(1<<i)>=deg[v])
            u=f[u][i];
    }
    if(u==v)return u;
    for(int i=20;i>=0;i--){
        if(f[u][i]!=0&&f[u][i]!=f[v][i]){
            u=f[u][i];v=f[v][i];
        }
    }
    return f[u][0];
}

void check(int z,int a,int b,int c){
//    cout<<z<<" "<<a<<" "<<b<<" "<<c<<"\n";
    int temp=0;
    int za=lca(z,a);
    int zb=lca(z,b);
    int zc=lca(z,c);
//    cout<<za<<" "<<zb<<" "<<zc<<"\n";
    temp+=deg[z]+deg[a]-2*deg[za];
    temp+=deg[z]+deg[b]-2*deg[zb];
    temp+=deg[z]+deg[c]-2*deg[zc];
//    cout<<temp<<"\n";
    if(temp<dislca){
        dislca=temp;
        realca=z;
    }
}

void dfs(int u,int dem,int pa){
    deg[u]=dem;
    for(int v:g[u]){
        if(v==pa)continue;
        f[v][0]=u;
        dfs(v,dem+1,u);
    }
}

void kaisa(){
//    freopen("TEST.INP","r",stdin);
//    freopen("TEST.OUT","w",stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    while(cin>>n){
        if(n==0)return;
        for(int i=1;i<n;i++){
            int u,v;cin>>u>>v;
            g[u].push_back(v);
            g[v].push_back(u);
        }
        R=1;
        for(int j=0;j<=20;j++){
            for(int i=1;i<=n;i++){
                f[i][j]=0;
            }
        }
        dfs(R,1,0);
        for(int j=1;j<=20;j++){
            for(int i=1;i<=n;i++){
                if(f[i][j-1]!=0){
                    f[i][j]=f[f[i][j-1]][j-1];
                }
            }
        }
        cin>>q;
        while(q--){
            char x;cin>>x;
            if(x=='!')
                cin>>R;
            else{
                int u,v;cin>>u>>v;
                k=lca(u,v);
//                cout<<lca(u,v)<<" "<<lca(u,R)<<" "<<lca(v,R)<<"aaa\n";
                dislca=oo;
                check(u,u,v,R);
                check(v,u,v,R);
                check(R,u,v,R);
                check(lca(u,v),u,v,R);
                check(lca(u,R),u,v,R);
                check(lca(v,R),u,v,R);
                cout<<realca<<"\n";
            }
        }
        for(int i=1;i<=n;i++){
            g[i].clear();
            deg[i]=0;
        }
    }
}

main()
{
    kaisa();
    return 0;
}