//hey bhagwan AC kara de :''}
#include<bits/stdc++.h>
using namespace std;

#define fo(i,n) for (int i = 0; i < n; ++i)
#define tr(i,n) for(auto i=n.begin();i!=n.end();i++)
#define w(t) while(t--)
#define ll long long int
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define fst ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL)
#define all(x) (x).begin(), (x).end()
const ll mod = 1000000007;
int a[10001];
int b[10001];
int c[10001];
int dp[10001][3];
int find(int n, int curr, int id)
{
    // cout<<dp[n][id]<<" ";
    if (n == 0)
    {

        if (id == 0) {
            int ans = curr + max(b[0], c[0]);
            return ans;
        }
        if (id == 1) {
            int ans = curr + max(a[0], c[0]);
            return ans;
        }
        if (id == 2) {
            int ans = curr + max(a[0], b[0]);
            return ans;
        }
    }
    if (dp[n][id] == -1)
    {
        if (id == 0){
            dp[n][id] = max(find(n - 1, curr + b[n], 1), find(n - 1, curr + c[n], 2));
            return dp[n][id];
        }
        else if (id == 1){
            dp[n][id] = max(find(n - 1, curr + a[n], 0), find(n - 1, curr + c[n], 2));
            return dp[n][id];
        }
        else{
            dp[n][id] = max(find(n - 1, curr + a[n], 0), find(n - 1, curr + b[n], 1));
            return dp[n][id];
        }
    }
    else
        return dp[n][id];

}

void solve()
{
    int n;
    cin >> n;
    memset(dp, -1, sizeof(dp));
    fo(i, n)
    cin >> a[i] >> b[i] >> c[i];

    int a1 = find(n - 1, 0, 0);
    int a2 = find(n - 1, 0, 1);
    int a3 = find(n - 1, 0, 2);
    cout << max({a1, a2, a3});
}

int main()
{
    fst;
    solve();
}