#include <bits/stdc++.h>
using namespace std;
#define int ll
#define ll long long
#define pii pair<ll, ll>
#define f first
#define s second
#define MX(a,b) a = max(a,b)
#define MN(a,b) a = min(a,b)
#define SZ(x) (int)(x).size()
#define ALL(x) (x).begin(), (x).end()
#define pb push_back
#define FOR(i,a,b) for (int i = a; i<b; ++i)
#define REP(i,n) FOR(i,0,n)
#define RREP(i,n) for (int i = n-1; i>=0; --i)
#define REP1(i,n) FOR(i,1,n+1)
#ifdef BALBIT
#define bug(...) cerr<<"#"<<__LINE__<<": "<<#__VA_ARGS__<<"- ", _do(__VA_ARGS__)
template<typename T> void _do( T && x) {cerr<<x<<endl;}
template<typename T, typename ...S> void _do( T && x, S && ...y) {cerr<<x<<", "; _do(y...);}
#else
#define bug(...)
#define endl '\n'
#endif // BALBIT
const int maxn = 2e3+5;
const ll inf = 0x3f3f3f3f3f3f3f3f;
int xpos[maxn], ypos[maxn];
int xv[maxn], yv[maxn];
ll dp[maxn][maxn];
vector<pii> clean(vector<int> raw) {
int n = SZ(raw);
vector<int> prefmin(n+2, inf), sufmin(n+2, inf);
REP(i, n) {
prefmin[i+1] = min(prefmin[i], raw[i]);
}
for (int i = n-2; i>=0; --i) {
sufmin[i] = min(sufmin[i+1], raw[i+1]);
}
vector<pii> re;
REP(i,n) {
if (raw[i] >= prefmin[i] && raw[i] >= sufmin[i]) {
// useless
continue;
}
re.pb({raw[i], i});
}
return re;
}
signed main(){
ios::sync_with_stdio(0), cin.tie(0);
bug(1,2);
int H,W; cin>>H>>W;
int n,m;
{
vector<int> tmp(H);
REP(i,H) cin>>tmp[i];
vector<pii> gx = clean(tmp);
n = SZ(gx);
REP(i, n) {
xpos[i] = gx[i].s, xv[i] = gx[i].f;
}
}
{
vector<int> tmp(W);
REP(i,W) cin>>tmp[i];
vector<pii> gy = clean(tmp);
m = SZ(gy);
REP(i, m) {
ypos[i] = gy[i].s, yv[i] = gy[i].f;
}
}
bug(n,m);
memset(dp, 0x3f, sizeof dp);
dp[0][0] = 0;
REP(i,n) {
REP(j,m) {
if (i) MN(dp[i][j], dp[i-1][j] + yv[j] * (xpos[i] - xpos[i-1]));
if (j) MN(dp[i][j], dp[i][j-1] + xv[i] * (ypos[j] - ypos[j-1]));
}
}
cout<<dp[n-1][m-1]<<endl;
}
