/*   @JUDGE_ID:   1705PZ   111   C */
#include <stdio.h>
#include <stdlib.h>

int main()
{
	int t1[21],t2[21],table[21][21];
	int i,j,n,temp;

	scanf("%d",&n);
	for(i = 0;i < n;i++)
	{
		scanf("%d",&temp);
		t1[temp] = i;
	}
	while(1)
	{
		for(i = 0;i < 21;i++)
			table[0][i] = table[i][0] = 0;

		if(scanf("%d",&temp) != 1) break;
		t2[temp] = 0;
		for(i = 1;i < n;i++)
		{
			scanf("%d",&temp);
			t2[temp] = i;
		}

		for(i = 1;i <= n;i++)
			for(j = 1;j <= n;j++)
			{
				if(t1[i] == t2[j])
					table[i][j] = table[i - 1][j - 1] + 1;
				else
					table[i][j] = table[i][j-1]>table[i-1][j]?table[i][j-1]:table[i-1][j];
			}
		printf("%d\n",table[n][n]);
	}
}
@END_OF_SOURCE_CODE