#include<iostream>
#include<string>
#include<sstream>
#include<algorithm>
using namespace std;
const int maxv=10000+10;
int in_order[maxv],post_order[maxv],lch[maxv],rch[maxv];
int n;
bool read_list(int *a)
{
	string line;
	if(!getline(cin,line)) return 0;
	stringstream ss(line);
	n=0;
	int x;
	while(ss>>x) a[n++]=x;
	return n>0;
}
int build(int L1,int R1,int L2,int R2)
{
	if(L1>R1) return 0;
	int root=post_order[R2];
	int p=L1;
	while(in_order[p]!=root) p++;
	int cnt=p-L1;
	lch[root]=build(L1,p-1,L2,L2+cnt-1);
	rch[root]=build(p+1,R1,L2+cnt,R2-1);
	return root;
}
int best,best_sum;
void dfs(int u,int sum)
{
	sum+=u;
	if(!lch[u]&&!rch[u])
	{
		if(sum<best_sum||(sum==best_sum&&u<best))
		{
			best=u;
			best_sum=sum;
		}
	}
	if(lch[u]) dfs(lch[u],sum);
	if(rch[u]) dfs(rch[u],sum);
}
int main()
{
	while(read_list(in_order))
	{
		read_list(post_order);
		build(0,n-1,0,n-1);
		best_sum=1000000000;
		dfs(post_order[n-1],0);
		cout<<best<<endl;
	}
	return 0;
}