#include <iostream>
#include <vector>
using namespace std;
const int maxn = 1e5 + 10;
const int INF = 2e9 + 5;
int n;
int a[maxn][4];
int happiness[maxn][4];
int main(){
    cin >> n;
    for(int i = 0; i < n; ++i) {
        cin >> a[i][0] >> a[i][1] >> a[i][2];
        happiness[i][0] = happiness[i][1] = happiness[i][2] = -INF;
    }
    happiness[0][0] = a[0][0];
    happiness[0][1] = a[0][1];
    happiness[0][2] = a[0][2];
    for(int day = 1; day < n; ++day) {
        for(int prev_activity = 0; prev_activity < 3; ++prev_activity) {
            for(int nxt_activity = 0; nxt_activity < 3; ++nxt_activity) {
                if(prev_activity == nxt_activity) {
                    // ista aktivnost ne smee da se pravi vo 2 posledovatelni denovi
                    continue;
                }
                happiness[day][nxt_activity] = max(happiness[day][nxt_activity], happiness[day - 1][prev_activity] + a[day][nxt_activity]);
            }
        }
    }
//    for(int i = 0; i < n; ++i) {
//        cout << "Day " << i + 1 << ":\n";
//        for(int j = 0; j < 3; ++j) {
//            cout << "Activity: " << j + 1 << " " << happiness[i][j] << endl;
//        }
//        cout << endl;
//    }
    cout << max(max(happiness[n - 1][0], happiness[n - 1][1]), happiness[n - 1][2]) << endl;
    return 0;
}
/*
 3
 10 20 30
 30 40 1005
 1  2  3
 */