#include "bits/stdc++.h"
using namespace std;
int dp[100001][3], a[100001][3];
int n;
// vector< vector<int> > dp(100001, vector<int> (3,-1);
// vector< vector<int> > dp(100001, vector<int> (3);
// same with a

int main() {
    cin >> n;
    for (int i = 0; i < n; i++)
        for (int j = 0; j < 3; j++) {
            cin >> a[i][j];

        }
    for (int j = 0; j < 3; j++)dp[n - 1][j] = a[n - 1][j];


    for (int i = n - 2; i >= 0; i--) {
        for (int j = 0; j < 3; j++) {
            dp[i][j] = a[i][j] + max(dp[i + 1][(j + 1) % 3], dp[i + 1][(j + 2) % 3]);
        }
    }
    int ans = 0;
    for (int i = 0; i < 3; i++)ans = max(ans, dp[0][i]);
    cout << ans << endl;

}