#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define fi first
#define se second
const int inf = 1e16 + 42;
void solve() {
int n, m;
cin >> n >> m;
vector<vector<int> > dp(1 + n, vector<int> (1 + m, inf));
vector<int> a(1 + n, 0), b(1 + m, 0);
for(int i = 1; i <= n; i++) {
cin >> a[i];
}
for(int j = 1; j <= m; j++) {
cin >> b[j];
}
dp[1][1] = 0;
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= m; j++) {
if(i != 1 || j != 1) {
dp[i][j] = min(dp[i - 1][j] + b[j], dp[i][j - 1] + a[i]);
}
}
}
cout << dp[n][m] << "\n";
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
solve();
}
