#include <bits/stdc++.h>
using namespace std;
#define FOR(i, l, r) for(int i = (l); i < (r); ++i)
#define ROF(i, r, l) for(int i = (r) - 1; i >= (l); --i)
#define all(v) begin(v), end(v)
#define rall(v) rbegin(v), rend(v)
#define sz(v) (int)v.size()
#define pb push_back
#define eb emplace_back
#define compact(v) v.erase(unique(all(v)), end(v))
#define mp make_pair
#define mt make_tuple
#define ff first
#define ss second
#define dbg(x) "[" #x " = " << (x) << "]"
#define readFile(task) freopen(task, "r", stdin)
#define writeFile(task) freopen(task, "w", stdout)
template<typename T>
bool minimize(T& a, const T& b){
if(a > b) return a = b, true;
return false;
}
template<typename T>
bool maximize(T& a, const T& b){
if(a < b) return a = b, true;
return false;
}
using ll = long long;
using db = double;
using ld = long double;
using ull = unsigned long long;
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using pd = pair<db, db>;
using vi = vector<int>;
using vb = vector<bool>;
using vstr = vector<string>;
using vl = vector<ll>;
using vd = vector<double>;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
void setIO(){
ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef LOCAL
readFile("task.inp");
writeFile("task.out");
#endif //LOCAL
}
const ll inf = 1e18;
int main(){
setIO();
int H, W;
cin >> H >> W;
vi A(H), B(W);
FOR(i, 0, H) cin >> A[i];
FOR(i, 0, W) cin >> B[i];
vector<vl> dp(H, vl(W, inf));
dp[0][0] = 0;
FOR(i, 0, H){
FOR(j, 0, W){
if(i > 0) minimize(dp[i][j], dp[i-1][j] + B[j]);
if(j > 0) minimize(dp[i][j], dp[i][j-1] + A[i]);
// cout << dbg(i) << dbg(j) << dbg(dp[i][j]) << '\n';
}
}
cout << dp[H-1][W-1] << '\n';
return 0;
}
