// Max subset sum of 2 array. No 2 elem should be consecutive.
// If 4th elem is from ar1 then we can't chose 3rd elem from either array and 4th elem shouldn't be from ar2.
#include<bits/stdc++.h>
using namespace std;
 
main(){
    int n;
    cin>>n;
    vector<int>a(n),b(n),dp(n);
    for(auto &it:a)cin>>it;
    for(auto &it:b)cin>>it;
    dp[0]=max(0,max(a[0],b[0]));
    dp[1]=max(dp[0],max(a[1],b[1]));
    for(int i=2;i<n;i++){
        dp[i]=max(dp[i-2]+max(a[i],b[i]),dp[i-1]);
    }
    cout<<dp[n-1]<<"\n";
}

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