#include <bits/stdc++.h>
#define MAX 500005
#define MOD (ll)(1e9+7)
#define INF (ll)(1e18)
#define inf (1987654321)
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
int n, m, q;
int a[100005], b[100005];
int mna[1005], mxa[1005];
int mnb[1005], mxb[1005];
ll dp[2005][2005];
int main()
{
ios::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m;
for(int i = 1; i <= n; ++i) cin >> a[i];
for(int i = 1; i <= m; ++i) cin >> b[i];
for(int i = 1; i <= 1000; ++i) {
mna[i] = mnb[i] = inf;
mxa[i] = mxb[i] = -1;
}
for(int i = 1; i <= n; ++i) mna[a[i]] = min(mna[a[i]], i), mxa[a[i]] = max(mxa[a[i]], i);
for(int i = 1; i <= m; ++i) mnb[b[i]] = min(mnb[b[i]], i), mxb[b[i]] = max(mxb[b[i]], i);
vector<int> row, col;
for(int i = 1; i <= 1000; ++i) {
if(mna[i] == inf) continue;
row.push_back(mna[i]);
if(mna[i] != mxa[i]) row.push_back(mxa[i]);
}
for(int i = 1; i <= 1000; ++i) {
if(mnb[i] == inf) continue;
col.push_back(mnb[i]);
if(mnb[i] != mxb[i]) col.push_back(mxb[i]);
}
sort(row.begin(), row.end());
sort(col.begin(), col.end());
for(int i = 0; i < (int)col.size(); ++i) dp[0][i] = (ll)a[row[0]] * (col[i] - 1);
for(int i = 1; i < (int)row.size(); ++i) {
for(int j = 0; j < (int)col.size(); ++j) {
if(j == 0) dp[i][0] = (ll)b[col[0]] * (row[i] - 1);
else {
dp[i][j] = inf;
dp[i][j] = min(dp[i][j], dp[i - 1][j] + (ll)b[col[j]] * (row[i] - row[i - 1]));
dp[i][j] = min(dp[i][j], dp[i][j - 1] + (ll)a[row[i]] * (col[j] - col[j - 1]));
}
}
}
cout << dp[row.size() - 1][col.size() - 1];
return 0;
}
