#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
const LL mod = 998244353;
void solve() {
LL n, m; cin>>n>>m;
vector<LL> a, b;
LL sum = 0;
for(LL i =1; i<=n+m-1; i++){
LL x; cin>>x;
a.push_back(x);
sum+= x;
}
for(LL i =1; i<=n+m-1; i++){
LL x; cin>>x;
b.push_back(x);
sum+=x;
}
if(n < m){
swap(n, m);
swap(a, b);
}
if(m == 1){
LL ans = 0;
for(int i = 0; i<n+m-1; i++){
ans+= min(a[i], b[n+m-2 - i]);
}
cout<<ans<<"\n";
return;
}
LL l = max(n, m);
vector<LL> Ax, Bx;
for(LL i = 1; i<= n - m; i++) Ax.push_back(0);
for(LL i = 0; i<a.size(); i++) Ax.push_back(a[i]);
for(LL i = 0; i<b.size(); i++) Bx.push_back(b[i]);
for(LL i = 1; i<= n - m; i++) Bx.push_back(0);
vector<LL> A, B;
for(LL i = 0; i<Ax.size(); i++) if(i%2 == 0) A.push_back(Ax[i]);
for(LL i = 0; i<Ax.size(); i++) {
if(l%2 == 1){
if(i%2 == 0) B.push_back(Bx[i]);
}
else if(i%2 == 1) B.push_back(Bx[i]);
}
if(A.size() < B.size()) swap(A, B);
// for(auto x: A) cout<<x<<" ";
// cout<<"\n";
// for(auto x: B) cout<<x<<" ";
// cout<<"\n";
for(LL i = 0; i<A.size()/2; i++){
A[i]+= A[A.size() - i - 1];
}
for(LL i = 0; i<B.size()/2; i++){
B[i]+= B[B.size() - i - 1];
}
for(LL i = 1; i<=A.size()/2; i++){
A[i]+= A[i-1];
}
for(LL i = 1; i<=B.size()/2; i++){
B[i]+= B[i-1];
}
A.insert(A.begin(), 0);
B.insert(B.begin(), 0);
// for(auto x: A) cout<<x<<" ";
// cout<<"\n";
// for(auto x: B) cout<<x<<" ";
// cout<<"\n";
LL mex1 = 0;
for(LL i = 0; i<=A.size()/2; i++){
mex1 = max<LL>(mex1, A[i] + B[A.size()/2-i]);
}
//cout<<mex1<<"\n";
//cout<<sum - mex<<"\n";
A.clear();
B.clear();
for(LL i = 0; i<Ax.size(); i++) if(i%2 == 1) A.push_back(Ax[i]);
for(LL i = 0; i<Ax.size(); i++) {
if(l%2 == 1){
if(i%2 == 1) B.push_back(Bx[i]);
}
else if(i%2 == 0) B.push_back(Bx[i]);
}
// for(auto x: A) cout<<x<<" ";
// cout<<"\n";
// for(auto x: B) cout<<x<<" ";
// cout<<"\n";
for(LL i = 0; i<A.size()/2; i++){
A[i]+= A[A.size() - i - 1];
}
for(LL i = 0; i<B.size()/2; i++){
B[i]+= B[B.size() - i - 1];
}
for(LL i = 1; i<=A.size()/2; i++){
A[i]+= A[i-1];
}
for(LL i = 1; i<=B.size()/2; i++){
B[i]+= B[i-1];
}
A.insert(A.begin(), 0);
B.insert(B.begin(), 0);
// for(auto x: A) cout<<x<<" ";
// cout<<"\n";
// for(auto x: B) cout<<x<<" ";
// cout<<"\n";
LL mex2 = 0;
for(LL i = 0; i<=A.size()/2; i++){
mex2 = max<LL>(mex2, A[i] + B[A.size()/2-i]);
}
//cout<<mex2<<"\n";
cout<<sum - mex1 - mex2<<"\n";
}
signed main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
LL T=1;
//cin >> T;
while (T--) solve();
return 0;
}
