#include 
#include 
using namespace std;
int n;
int mat[100005][3];
int memo[100005][3];
int vacation(int i, int activity) {
    if(i == n) {
        return 0;
    }
    if(memo[i][activity] != -1) {
        return memo[i][activity];
    }
    int result = 0;
    for(int j = 0; j < 3; j++) {
        if(activity != j) {
            result = max(result, vacation(i + 1, j) + mat[i][activity]);
        }
    }
    return memo[i][activity] = result;
}
int main() {
    cin >> n;
    for(int i = 0; i < n; i++) {
        cin >> mat[i][0] >> mat[i][1] >> mat[i][2];
        memo[i][0] = memo[i][1] = memo[i][2] = -1;
    }
    cout << max(vacation(0, 0) , max(vacation(0, 1) , vacation(0, 2)) ) << endl;
    return 0;
}
// fib(7) = fib(6) + fib(5)
//