#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
#define pb push_back
#define pii pair<int, int>
#define pll pair<ll, ll>
#define st first
#define nd second
#define ordered_set tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
#define debug false
const int MAXH = 1000 + 17;
const ll INF = ll(1000 * 1000 * 1000) * ll(1000 * 1000 * 1000);
ll a[MAXH][2];
ll dp[MAXH][MAXH];
int main () {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int h, w;
cin >> h >> w;
for (int i = 0; i < h; i ++) {
cin >> a[i][0];
}
for (int i = 0; i < w; i ++) {
cin >> a[i][1];
}
for (int i = 0; i < h; i ++) {
for (int j = 0; j < w; j ++) {
dp[i][j] = INF;
}
}
dp[h - 1][w - 1] = 0;
for (int i = h - 1; i >= 0; i --) {
for (int j = w - 1; j >= 0; j --) {
if (i + 1 < h) {
dp[i][j] = min(dp[i][j], dp[i + 1][j] + a[j][1]);
}
if (j + 1 < w) {
dp[i][j] = min(dp[i][j], dp[i][j + 1] + a[i][0]);
}
}
}
cout << dp[0][0] << "\n";
return 0;
}
