#include<iostream>
#include<algorithm>
using namespace std;

int main(){
	int len, current;
	while(cin>>len){
		int dp[len+1][len+1], A[len+1];
		for(int i=0; i<len; i++) dp[0][i] = dp[i][0] = 0;
		for(int i=1; i<=len; i++) cin>>A[i];
		for(int j=1; j<=len; j++){
			cin>>current;
			for(int i=1; i<=len; i++){
				if(A[i] == current) dp[i][j] = dp[i-1][j-1]+1;
				else dp[i][j] = dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
			}
		}
		cout<<dp[len][len];
	}
}