题目：

/**
* From:
* Qingdao Agricultural University
* Created by XiangwangAcmer
* Date : 2019-10-02-11.57.31
* Talk is cheap.Show me your code.
*/
#include<iostream>
#include<cstring>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<queue>
#include<cmath>
#include<cctype>
#include<stack>
#include<map>
#include<string>
#include<cstdlib>
#define ll long long
using namespace std;
const ll maxn = 1e6 + 5;
const ll minn = 1e9 + 5;
const ll mod = 1000000007;
const int INF = 0x3f3f3f3f;
const long long LIMIT = 4294967295LL;
vector<int>v[maxn];
int dp[maxn];
int G[500][500];
bool row[maxn], col[maxn];
bool flag = 0;
queue<int>q;
map<string,int>dict;
int ids;
int find(string a) {
    if(dict.count(a)==0)
        dict [a] = ++ids;
    else return
            dict[a];
}
int main() {
    ios::sync_with_stdio(false);
    int n;
    ids = 0;
    cin >> n;
    string a,b;
    for(int i = 0; i < n; i++) {
        cin>>a>>b;
        int x = find(a), y = find(b);
        G[x][y] = G[y][x] = 1;
    }
    int m;
    cin>>m;
    while(m--){
        cin>>a>>b;
        if(G[find(a)][find(b)])
            cout<<"Yes"<<endl;
        else cout<<"No"<<endl;
    }
        return 0;
}