#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <vector>
#include <set>
#define NMAX 200005
#define LMAX (1<<16)
#define pii pair <int,int>
#define pb push_back
#define mp make_pair
#define f first
#define s second
# define verf ++poz == LMAX ? fread ( ch, 1, LMAX, stdin ), poz = 0 : 0
using namespace std; 
int n,B[NMAX],dad[NMAX],st[NMAX],dr[NMAX],r,best[NMAX],E[NMAX],ap[NMAX],poz,act,rez;
vector <int> A[NMAX],C[NMAX];
vector < pair <pii,int> > D[NMAX],F[NMAX];
set <pii> H,G;
set <pii> :: iterator it;
char viz[NMAX],ch[LMAX];
inline int cif(char x)
{
	return x>='0' && x<='9';
}
inline void citeste ( int &x )
{
    int semn = 1;
    if ( ch[0] == '\0' ) 
		fread ( ch, 1, LMAX, stdin ) ;
    else 
		for ( ; (ch[poz] < '0' || ch[poz] > '9') && ch[poz] != '-' ; verf ) ;
    for ( x = 0 ; (ch[poz] >= '0' && ch[poz] <= '9') || ch[poz] == '-'; (ch[poz] == '-' ? semn = -1 : x = x * 10 + ch[poz] - '0'), verf ) ;
    x *= semn;
}

void read()
{
	scanf("%d",&n);
	int i,x,y,semn,poz=0;
	for (i=1; i<n; i++)
	{
		scanf("%d%d",&x,&y);
		A[x].pb(y);
		A[y].pb(x);
	}
	for (i=1; i<=n; i++)
		citeste(B[i]);
}
void dfs(int nod)
{
	viz[nod]=1;
	st[nod]=++r;
	it=H.lower_bound(mp(B[nod],0));
	if (it!=H.end())
		C[(*it).s].pb(nod);
	H.insert(mp(B[nod],nod));
	
	int i,vec;
	for (i=0; i<A[nod].size(); i++)
	{
		vec=A[nod][i];
		if (!viz[vec])
			dfs(vec);
	}
	H.erase(mp(B[nod],nod));
	dr[nod]=r;
}
void prepare()
{
	int i,j,vec;
	for (i=1; i<=n; i++)
	{
		for (j=0; j<C[i].size(); j++)
		{
			vec=C[i][j];
			D[i].pb(mp(mp(st[vec],dr[vec]),vec));
			F[i].pb(mp(mp(dr[vec],st[vec]),vec));
		}
		sort(D[i].begin(),D[i].end());
		sort(F[i].begin(),F[i].end());
	}
}
inline int max(int x,int y)
{
	return x>y ? x : y;
}
void dfs2(int nod)
{
	viz[nod]=1;
	int i,j,vec,vec2;
	for (i=0; i<A[nod].size(); i++)
	{
		vec=A[nod][i];
		if (!viz[vec])
			dfs2(vec);
	}
	
	poz=-1; act=0;
	for (i=0; i<D[nod].size(); i++)
	{
		vec=D[nod][i].s; 
		ap[vec]=i;
		E[i]=0;
	}
	for (i=0; i<D[nod].size(); i++)
	{
		vec=D[nod][i].s;
		while (poz+1<F[nod].size() && F[nod][poz+1].f.f<st[vec])
		{
			poz++;
			act=max(act,E[ap[F[nod][poz].s]]);
		}
		E[i]=act+best[vec];
	}
	for (i=0; i<D[nod].size(); i++)
		best[nod]=max(best[nod],E[i]);
	best[nod]++;
}
void find_sol()
{
	int i;
	for (i=1; i<=n; i++)
		rez=max(rez,best[i]);
}
int main()
{
	freopen("guvern.in","r",stdin);
	freopen("guvern.out","w",stdout);
	read();
	dfs(1);
	prepare();
	memset(viz,0,sizeof(viz));
	dfs2(1);
	find_sol();
	printf("%d\n",rez);
	return 0;
}