#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define fi first
#define se second
typedef long long ll;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
mt19937 rnf(2106);
const int N = 100005, M = 1004;
const ll INF = 1000000009000000009;
int n, m;
int a[N], b[N];
bool c[M];
ll dp[M][M];
void solv()
{
cin >> n >> m;
for (int i = 1; i <= n; ++i)
{
cin >> a[i];
}
for (int i = 1; i <= m; ++i)
{
cin >> b[i];
}
vector<int> aa;
map<int, bool> c;
for (int i = n; i >= 1; --i)
{
//if (c[a[i]])
// continue;
aa.push_back(i);
c[a[i]] = true;
}
aa.push_back(1);
vector<int> bb;
c.clear();
for (int j = m; j >= 1; --j)
{
//if (c[b[j]])
// continue;
bb.push_back(j);
c[b[j]] = true;
}
bb.push_back(1);
for (int i = 0; i < sz(aa); ++i)
{
for (int j = 0; j < sz(bb); ++j)
{
dp[i][j] = INF;
}
}
dp[0][0] = 0;
for (int i = 0; i < sz(aa); ++i)
{
for (int j = 0; j < sz(bb); ++j)
{
if (i + 1 < sz(aa))
dp[i + 1][j] = min(dp[i + 1][j], dp[i][j] + (aa[i] - aa[i + 1]) * 1LL * b[bb[j]]);
if (j + 1 < sz(bb))
dp[i][j + 1] = min(dp[i][j + 1], dp[i][j] + (bb[j] - bb[j + 1]) * 1LL * a[aa[i]]);
}
}
cout << dp[sz(aa) - 1][sz(bb) - 1] << "\n";
}
int main()
{
#ifdef SOMETHING
freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
#endif // SOMETHING
ios_base::sync_with_stdio(false), cin.tie(0);
int tt = 1;
//cin >> tt;
while (tt--)
{
solv();
}
return 0;
}
