#include<bits/stdc++.h>
using namespace std;
#define maxn 110000
int n,k,q,sum;
int deep[110001],tot;
int head[110001],dp[110001][20];
map<string,int>mmp;
map<int,string>out;
string str1,str2;
struct node
{
    int v,to;
} edge[maxn*2];
void add(int u,int v)
{
    edge[++tot].v=v;
    edge[tot].to=head[u];
    head[u]=tot;
}
void dfs(int cur,int pre)
{
    deep[cur]=deep[pre]+1;
    dp[cur][0]=pre;
    for(int i=1; (1<<i)<=deep[cur]; i++)
        dp[cur][i]=dp[dp[cur][i-1]][i-1];
    for(int i=head[cur]; i!=-1; i=edge[i].to)
        if(edge[i].v!=pre)
            dfs(edge[i].v,cur);
}
int lca(int x,int y)
{
    if(deep[x]<deep[y])
        swap(x,y);
    for(int i=k; i>=0; i--)
        if(deep[x]-(1<<i)>=deep[y])
            x=dp[x][i];
    if(x==y)
        return x;
    for(int i=k; i>=0; i--)
        if(dp[x][i]!=dp[y][i])
        {
            x=dp[x][i];
            y=dp[y][i];
        }
    if(dp[x][0]==dp[y][0])
        return dp[x][0];
    else
        return -1;
}
int main()
{
    cin>>n;
    memset(head,-1,sizeof(head));
    for(int i=0; i<n; i++)
    {
        cin>>str1>>str2;
        if(mmp[str1]==0)
        {
            mmp[str1]=++sum;
            out[sum]=str1;
        }
        if(mmp[str2]==0)
        {
            mmp[str2]=++sum;
            out[sum]=str2;
        }
        add(mmp[str1],mmp[str2]);
    }
    k=log(sum)/log(2);
    dfs(1,0);
    cin>>q;
    while(q--)
    {
        cin>>str1>>str2;
        if(str1==str2)
            cout<<str2<<endl;
        else if(lca(mmp[str1],mmp[str2])==-1)
            cout<<-1<<endl;
        else
            cout<<out[lca(mmp[str1],mmp[str2])]<<endl;
    }
    return 0;
}