#include <bits/stdc++.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
using mint = atcoder::modint998244353;
using maxt = atcoder::modint1000000007;

struct power {
  ll damage, attack;
};

int main() {
	int N;
	cin >> N;
	vector<vector<ll>> A(N, vector<ll>(3));
	for(vector<ll> &o : A) {
	  for(ll &p : o) {
	    cin >> p;
	  }
	}
	vector<vector<power>> dp(N + 1, vector<power>(3));
	for(int i = 1; i <= N; i++) {
	  dp.at(i).at(0).attack = max(dp.at(i - 1).at(1).attack, dp.at(i - 1).at(2).attack) + A.at(i - 1).at(0);
	  dp.at(i).at(0).damage = max(dp.at(i - 1).at(1).damage, dp.at(i - 1).at(2).damage) + dp.at(i).at(0).attack;
	  dp.at(i).at(1).attack = max(dp.at(i - 1).at(0).attack, dp.at(i - 1).at(2).attack) + A.at(i - 1).at(1);
	  dp.at(i).at(1).damage = max(dp.at(i - 1).at(0).damage, dp.at(i - 1).at(2).damage) + dp.at(i).at(1).attack;
	  dp.at(i).at(2).attack = max(dp.at(i - 1).at(0).attack, dp.at(i - 1).at(1).attack) + A.at(i - 1).at(2);
	  dp.at(i).at(2).damage = max(dp.at(i - 1).at(0).damage, dp.at(i - 1).at(1).damage) + dp.at(i).at(2).attack;
	  for(power &o : dp.at(i)) {
	    if(o.attack > 0) {
	      o.attack--;
	    }
	  }
	}
	cout << max(max(dp.at(N).at(0).damage, dp.at(N).at(1).damage), dp.at(N).at(2).damage) << endl;
}