#include <bits/stdc++.h> // pA
#define IO ios::sync_with_stdio(false);cin.tie(0);
#define debug(x) cerr << #x << " = " << (x) << ' '
#define endl cerr << '\n'
#define all(v) (v).begin(), (v).end()
#define SZ(v) (ll)(v).size()
#define lowbit(x) (x)&-(x)
#define pb emplace_back
#define F first
#define S second
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
const int N = 1005;
const ll INF = 1e18;
ll a[N], b[N], dp[N][N];
int main(void)
{ IO
ll n, i, m, j;
cin >> n >> m;
for (i=1; i <= n; ++i) cin >> a[i];
for (i=1; i <= m; ++i) cin >> b[i];
for (i=0; i <= n; ++i) for (j=0; j <= m; ++j) dp[i][j] = INF;
dp[1][1] = 0;
for (i=1; i <= n; ++i)
{
for (j=1; j <= m; ++j)
{
dp[i][j] = min({dp[i][j], dp[i-1][j]+b[j], dp[i][j-1] + a[i]});
//cerr << dp[i][j] << ' ';
} //endl;
}
cout << dp[n][m] << '\n';
return 0;
}
