#include<bits/stdc++.h>
using namespace std;

#define ff              first
#define ss              second
#define int             long long
// #define ll              long long
#define pb              push_back
#define mp              make_pair
#define pii             pair<int,int>
#define vi              vector<int>
#define mii             map<int,int>
#define pqb             priority_queue<int>
#define pqs             priority_queue<int,vi,greater<int> >
#define setbits(x)      __builtin_popcountll(x)
#define zrobits(x)      __builtin_ctzll(x)
#define mod             1000000007
#define inf             998244353
#define endl            "\n"
#define ps(x,y)         fixed<<setprecision(y)<<x
#define mk(arr,n,type)  type *arr=new type[n];
#define w(x)            int x; cin>>x; while(x--)
mt19937                 rng(chrono::steady_clock::now().time_since_epoch().count());
#define for0(i, n) for (int i = 0; i < n; i++)
#define for1(i, n) for (int i = 1; i <= n; i++)
int max(int a, int b) {if (a > b) return a; else return b;}
int min(int a, int b) {if (a < b) return a; else return b;}
// #DEBUG
void __print(int x) {cout << x;}
void __print(char x) {cout << '\'' << x << '\'';}
void __print(const char *x) {cout << '\"' << x << '\"';}
void __print(const string &x) {cout << '\"' << x << '\"';}
void __print(bool x) {cout << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cout << '{'; __print(x.first); cout << ','; __print(x.second); cout << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cout << '{'; for (auto &i : x) cout << (f++ ? "," : ""), __print(i); cout << "}";}
void _print() {cout << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cout << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cout << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
// ###################################################################
int pow(int a, int b, int m) {
  int r = 1, e = a;
  while (b) {
    if (b & 1) r = (r * e) % m;
    e = (e * e) % m;
    b >>= 1;
  }
  return r;
}
void fast()
{
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

}
// First write recursive with no ristrictions;
// Then apply ristrictions; (What can we do? and Can we do it?)
// We are adding mod because sometimes ans could be negeative (So always add mod when substracting 2 mod answers)
int n;
int a[100005][4];
int dp[100005][4];

int solve(int day, int flag) {
  if (day == n) {
    return 0;
  }
  if (dp[day][flag] != -1) {
    return dp[day][flag];
  }
  int maxi = 0;
  if (flag == 0) {
    maxi = max(maxi, a[day][1] + solve(day + 1, 1));
    maxi = max(maxi, a[day][2] + solve(day + 1, 2));
    maxi = max(maxi, a[day][3] + solve(day + 1, 3));
  }
  if (flag == 1) {
    maxi = max(maxi, a[day][2] + solve(day + 1, 2));
    maxi = max(maxi, a[day][3] + solve(day + 1, 3));

  }
  if (flag == 2) {
    maxi = max(maxi, a[day][1] + solve(day + 1, 1));
    maxi = max(maxi, a[day][3] + solve(day + 1, 3));

  }
  if (flag == 3) {
    maxi = max(maxi, a[day][1] + solve(day + 1, 1));
    maxi = max(maxi, a[day][2] + solve(day + 1, 2));

  }
  return dp[day][flag] = maxi;
}
int32_t main() {
  fast();
  cin >> n;
  for (int i = 0; i < n; i++) {
    for (int j = 1; j <= 3; j++) {
      cin >> a[i][j];
    }
  }
  memset(dp, -1, sizeof(dp));
  cout << solve(0, 0) << endl;
}

Measured memory_bytes: 14336