#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define int long long
#define all(a) begin(a),end(a)
const int mxN = (int)1e3+10;
bool vis[mxN];
int n, m, dp[mxN][mxN];
int a[100010], b[100010];
vector<array<int,2>> A, B;
int32_t main()
{
cin >> n >> m;
for(int i = 0; i < n; i++) cin >> a[i];
for(int i = 0; i < m; i++) cin >> b[i];
for(int i = n-1; i >= 0; i--)
if(n<=1000 or !i or !vis[a[i]])
vis[a[i]]=1, A.pb({a[i],i});
memset(vis,0,sizeof(vis));
for(int i = m-1; i >= 0; i--)
if(m<=1000 or !i or !vis[b[i]])
vis[b[i]]=1, B.pb({b[i],i});
reverse(all(A)), reverse(all(B));
n = A.size(), m = B.size();
memset(dp,63,sizeof(dp)); dp[1][1] = 0;
for(int i = 1; i <= n; i++){
for(int j = 1; j <= m; j++){
if(i>1) dp[i][j] = min(dp[i][j], dp[i-1][j]+B[j-1][0]*(A[i-1][1]-A[i-2][1]));
if(j>1) dp[i][j] = min(dp[i][j], dp[i][j-1]+A[i-1][0]*(B[j-1][1]-B[j-2][1]));
}
}
cout << dp[n][m];
}
