#include <iostream>
#include <string.h>
using namespace std;
int dp[1000];
 
int main() {
	// your code goes here
	memset(dp,-1,sizeof(dp));
	int ps[4];
	int ts[4];
	dp[0]=0;
	int n;
	cin>>n;
	for(int i=0;i<4;i++){
		cin>>ps[i];
	}
	for(int i=0;i<4;i++){
		cin>>ts[i];
	}
	for(int i=0;i<4;i++){
		int p1=ps[i];
		int t1=ts[i];
		for(int j=0;j<n;j++){
			if(dp[j]==-1)continue;
			int p2=dp[j]+p1;
			if(dp[j+t1]==-1 || p2<dp[j+t1])dp[j+t1]=p2;
		}
	}
	int ans=10000000;
	for(int i=n;i<1000;i++){
		if(dp[i]!=-1 && dp[i]<ans)ans=dp[i];
	}
	cout<<ans<<endl;
	return 0;
}

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