/* -*- coding: utf-8 -*-
 *
 * 2982.cc:  No.2982 Logic Battle - yukicoder
 */

#include<cstdio>
#include<algorithm>
#include<utility>

using namespace std;

/* constant */

const int MAX_N = 5000;

/* typedef */

using ll = long long;
using pll = pair<ll,ll>;

/* global variables */

int as[MAX_N][3];
pll dp[MAX_N + 1][3];

/* subroutines */

template <typename T>
inline void setmax(T &a, T b) { if (a < b) a = b; }

/* main */

int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++)
    for (int j = 0; j < 3; j++) scanf("%d", as[i] + j);

  for (int i = 0; i < n; i++)
    for (int j = 0; j < 3; j++) {
      int j1 = (j + 1) % 3, j2 = (j + 2) % 3;
      auto [s1, x1] = dp[i][j1];
      auto [s2, x2] = dp[i][j2];
      ll d1 = s1 + x1 + as[i][j], d2 = s2 + x2 + as[i][j];
      if (d1 >= d2) dp[i + 1][j] = {d1, max(0LL, x1 + as[i][j] - 1)};
      else dp[i + 1][j] = {d2, max(0LL, x2 + as[i][j] - 1)};
    }

  ll maxd = max(dp[n][0].first, max(dp[n][1].first, dp[n][2].first));
  printf("%lld\n", maxd);
  
  return 0;
}