#include<bits/stdc++.h>
using namespace std;
#define int long long
ifstream fin("running.in");
ofstream fout("running.out");
#define cin fin
#define cout fout
int n,x;
struct score{
	int a,b,real;
}s[50010];
int sum[50010];
signed main(){
	cin>>n>>x;
	for(int i=1;i<=n;i++)cin>>s[i].a;
	for(int i=1;i<=n;i++){
		cin>>s[i].b;
		s[i].real=s[i].a-s[i].b;
		sum[i]=sum[i-1]+s[i].real;
	}
	int res=x*sum[n];
	if(res<=10000){
		cout<<res<<endl;
		exit(0);
	}
	cout<<"2 hard 4 me"<<endl;
	return 0;
}