#include <iostream>
#include <vector>
using namespace std;
using ll = long long;
int n, m;
vector <ll> a(2e5, 0);
vector <ll> b(2e5, 0);
vector <vector <ll>> dp(2e3, vector <ll>(2e3, 1e18));
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m;
for (int i = 1; i <= n; i++) cin >> a[i];
for (int i = 1; i <= m; i++) cin >> b[i];
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
if (i * j == 1) continue;
dp[i][j] = min(dp[i - 1][j] + b[j], dp[i][j - 1] + a[i]);
}
}
cout << dp[n][m];
}
