a457

/* a457             */
/* AC (38ms, 1.2MB) */
#include <cstdio>
#include <algorithm>
#define S first
#define R second
using namespace std;
const int MAXN = 100001;
typedef long long int64;
pair <int, int> obj[MAXN];
int b[MAXN];
int k, m;
int64 merge_sort(int l, int r)
{
    int64 res = 0;
    if(l < r)
    {
        int mid = (l + r) >> 1;
        res = merge_sort(l, mid) + merge_sort(mid + 1, r);
        for(int i = l, j = mid + 1, k = l; i <= mid || j <= r; k++)
            if(j == r + 1 || i <= mid && obj[i].R <= obj[j].R) b[k] = obj[i++].R;
            else
            {
                b[k] = obj[j++].R;
                res += mid - i + 1;
            }
        for(int i = l; i <= r; i++) obj[i].R = b[i];
    }
    return res;
}
int main()
{
    scanf("%d %d", &k, &m);
    for(int i = 0; i < k; i++) scanf("%d", &obj[i].S);
    for(int i = 0; i < k; i++) scanf("%d", &obj[i].R);
    sort(obj, obj + k);
    printf("%lld", merge_sort(0, k - 1));
    return 0;
}