#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ull = unsigned long long;
const int INF = 2001001001;
const ll LINF = 9001001001001001001;

#define rep(i, n) for (int i = 0; (i) < (n); (i)++)
#define rep1(i, n) for (int i = 1; (i) < (n + 1); (i)++)
#define all(a) (a).begin(), (a).end()

int main(){
  ll N;
  cin >> N;

  ll A[5009][4];
  rep1(i,N){
    rep1(j,3){
      cin >> A[i][j];
    }
  }

  ll dp[5009][4] = {};
  ll attack[5009][4] = {};

  rep1(i,N){
    if(dp[i-1][2]+attack[i-1][2] > dp[i-1][3]+attack[i-1][3]){
      dp[i][1] = dp[i-1][2]+attack[i-1][2]+A[i][1];
      attack[i][1] = max(attack[i-1][2]+A[i][1]-1, 0LL);
    } else {
      dp[i][1] = dp[i-1][3]+attack[i-1][3]+A[i][1];
      attack[i][1] = max(attack[i-1][3]+A[i][1]-1, 0LL);
    }

    if(dp[i-1][1]+attack[i-1][1] > dp[i-1][3]+attack[i-1][3]){
      dp[i][2] = dp[i-1][1]+attack[i-1][1]+A[i][2];
      attack[i][2] = max(attack[i-1][1]+A[i][2]-1, 0LL);
    } else {
      dp[i][2] = dp[i-1][3]+attack[i-1][3]+A[i][2];
      attack[i][2] = max(attack[i-1][3]+A[i][2]-1, 0LL);
    }

    if(dp[i-1][1]+attack[i-1][1] > dp[i-1][2]+attack[i-1][2]){
      dp[i][3] = dp[i-1][1]+attack[i-1][1]+A[i][3];
      attack[i][3] = max(attack[i-1][1]+A[i][3]-1, 0LL);
    } else {
      dp[i][3] = dp[i-1][2]+attack[i-1][2]+A[i][3];
      attack[i][3] = max(attack[i-1][2]+A[i][3]-1, 0LL);
    }
  }

  cout << max({dp[N][1], dp[N][2], dp[N][3]}) << endl;
}