#include <bits/stdc++.h> using namespace std; typedef long long ll; #define rep(i, n) for (int i = 0; i < (n); i++) #define st first #define nd second #define pb push_back #define pii pair<int, int> #define pll pair<ll, ll> #define all(a) a.begin(), a.end() const ll INF = 1e18; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int n, m; cin >> n >> m; ll A[n]; ll B[m]; rep(i, n) cin >> A[i]; rep(i, m) cin >> B[i]; vector<pll> xda; vector<pll> xdb; rep(i, n - 1) { pll pom = {A[i + 1] - A[i], 1ll}; while (!xda.empty() && (xda.back().st * pom.nd) >= (pom.st * xda.back().nd)) { pom.st += xda.back().st; pom.nd += xda.back().nd; xda.pop_back(); } xda.pb(pom); } rep(i, m - 1) { pll pom = {B[i + 1] - B[i], 1ll}; while (!xdb.empty() && (xdb.back().st * pom.nd) >= (pom.st * xdb.back().nd)) { pom.st += xdb.back().st; pom.nd += xdb.back().nd; xdb.pop_back(); } xdb.pb(pom); } int sza = xda.size(); int szb = xdb.size(); int ita = 0; int itb = 0; ll x = 0; ll y = 0; ll ans = 0ll; while (ita < sza || itb < szb) { if (ita == sza) { ans += (A[x] * xdb[itb].nd); y += xdb[itb].nd; itb++; } else if (itb == szb) { ans += (B[y] * xda[ita].nd); x += xda[ita].nd; ita++; } else { if ((xda[ita].st * xdb[itb].nd) > (xdb[itb].st * xda[ita].nd)) { ans += (A[x] * xdb[itb].nd); y += xdb[itb].nd; itb++; } else { ans += (B[y] * xda[ita].nd); x += xda[ita].nd; ita++; } } } cout << ans << '\n'; return 0; }