简单贪心。。。。
#include <iostream>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <bitset>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <climits>
#include <cstdlib>
#include <cmath>
#include <time.h>
#define maxn 100005
#define maxm 40005
#define eps 1e-10
#define mod 10000007
#define INF 1e9
#define lowbit(x) (x&(-x))
#define mp make_pair
#define ls o<<1
#define rs o<<1 | 1
#define lson o<<1, L, mid
#define rson o<<1 | 1, mid+1, R
typedef long long LL;
typedef unsigned long long ULL;
//typedef int LL;
using namespace std;
LL qpow(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base;base=base*base;b/=2;}return res;}
LL powmod(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base%mod;base=base*base%mod;b/=2;}return res;}
void scanf(int &__x){__x=0;char __ch=getchar();while(__ch==' '||__ch=='\n')__ch=getchar();while(__ch>='0'&&__ch<='9')__x=__x*10+__ch-'0',__ch = getchar();}
LL gcd(LL _a, LL _b){if(!_b) return _a;else return gcd(_b, _a%_b);}
//head
struct node
{
char f[60];
char s[60];
}name[maxn];
int rank[maxn];
char now[60];
int n;
void read(void)
{
for(int i = 1; i <= n; i++) scanf("%s%s", name[i].f, name[i].s);
for(int i = 1; i <= n; i++) scanf("%d", &rank[i]);
}
void work(void)
{
int ok = 1;
now[0] = 0;
for(int i = 1; i <= n && ok; i++) {
int t =rank[i];
int a = strcmp(name[t].f, now), b = strcmp(name[t].s, now);
if(a > 0 && b > 0) {
if(strcmp(name[t].f, name[t].s) > 0) strcpy(now, name[t].s);
else strcpy(now, name[t].f);
}
else if(a > 0) strcpy(now, name[t].f);
else if(b > 0) strcpy(now, name[t].s);
else ok = 0;
}
if(ok) printf("YES\n");
else printf("NO\n");
}
int main(void)
{
while(scanf("%d", &n)!=EOF) {
read();
work();
}
return 0;
}
