#include<bits/stdc++.h>
#define fi first
#define se second
#define eb emplace_back
#define ep emplace
#define all(x) (x).begin(),(x).end()
using namespace std;
typedef long long ll;
typedef pair<int,int> pi;
typedef pair<ll,ll> pl;
const ll INF=1e18;
const ll mod=1e9+7;
const ll mxn=1005;
int h,w,a[mxn],b[mxn];
ll dp[mxn][mxn];
int main()
{
ios::sync_with_stdio(0); cin.tie(0);
cin>>h>>w;
for (int i=1;i<=h;i++) cin>>a[i];
for (int i=1;i<=w;i++) cin>>b[i];
for (int i=1;i<=h;i++)
for(int j=1;j<=w;j++)
{
if(i==1 && j==1) continue;
ll x=(i>1?dp[i-1][j]+b[j]:INF);
ll y=(j>1?dp[i][j-1]+a[i]:INF);
dp[i][j]=min(x,y);
}
cout<<dp[h][w];
}
