#include <bits/stdc++.h> // Include every standard library
using namespace std;
int dirx[8] = {-1, 0, 0, 1, -1, -1, 1, 1};
int diry[8] = {0, 1, -1, 0, -1, 1, -1, 1};
#define FOREACH(a, b) for (auto &(a) : (b))
#define MAX(a, b) a = max(a, b)
#define MIN(a, b) a = min(a, b)
#define sqr(x) ((LL)(x) * (x))
#define RESET(a, b) memset(a, b, sizeof(a))
#define ALL(v) v.begin(), v.end()
#define ALLA(arr, sz) arr, arr + sz
#define sort(v) sort(ALL(v))
#define REVERSE(v) reverse(ALL(v))
#define SORTA(arr, sz) sort(ALLA(arr, sz))
#define REVERSEA(arr, sz) reverse(ALLA(arr, sz))
#define TC(t) while (t--)
#define ms(s, n) memset(s, n, sizeof(s))
#define f(i, a, b) for (int i = (a); i < (b); i++)
#define FORn(i, a, b) for (int i = (a); i <= (b); i++)
#define FORd(i, a, b) for (int i = (a)-1; i >= (b); i--)
#define FORall(it, a) for (__typeof((a).begin()) it = (a).begin(); it != (a).end(); it++)
#define size(a) int((a).size())
#define present(t, x) (t.find(x) != t.end())
#define all(a) (a).begin(), (a).end()
#define uni(a) (a).erase(unique(all(a)), (a).end())
#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define prec(n) fixed << setprecision(n)
#define bit(n, i) (((n) >> (i)) & 1)
#define bitcount(n) __builtin_popcountll(n)
#define IOS                  \
    ios::sync_with_stdio(0); \
    cin.tie(0);              \
    cout.tie(0);
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pi;
typedef vector<ll> vi;
typedef vector<pi> vii;
typedef vector<vector<int>> vvi;
const int MOD = (int)1e9 + 7;
const int MOD2 = MOD + 2; //1007681537;
const int INF = (int)1e9;
const ll LINF = (ll)1e18;
const ld PI = acos((ld)-1);
const ld EPS = 1e-9;
inline ll gcd(ll a, ll b)
{
    ll r;
    while (b)
    {
        r = a % b;
        a = b;
        b = r;
    }
    return a;
}
inline ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
inline ll fpow(ll n, ll k, int p = MOD)
{
    ll r = 1;
    for (; k; k >>= 1)
    {
        if (k & 1)
            r = r * n % p;
        n = n * n % p;
    }
    return r;
}
template <class T>
inline int chkmin(T &a, const T &val) { return val < a ? a = val, 1 : 0; }
template <class T>
inline int chkmax(T &a, const T &val) { return a < val ? a = val, 1 : 0; }
inline ll isqrt(ll k)
{
    ll r = sqrt(k) + 1;
    while (r * r > k)
        r--;
    return r;
}
inline ll icbrt(ll k)
{
    ll r = cbrt(k) + 1;
    while (r * r * r > k)
        r--;
    return r;
}
inline void addmod(int &a, int val, int p = MOD)
{
    if ((a = (a + val)) >= p)
        a -= p;
}
inline void submod(int &a, int val, int p = MOD)
{
    if ((a = (a - val)) < 0)
        a += p;
}
inline int mult(int a, int b, int p = MOD) { return (ll)a * b % p; }
inline int inv(int a, int p = MOD) { return fpow(a, p - 2, p); }
inline int sign(ld x) { return x < -EPS ? -1 : x > +EPS; }
inline int sign(ld x, ld y) { return sign(x - y); }
int modulo(int a, int b) { return (a % b + b) % b; }
#define db(x) cerr << #x << " = " << (x) << " ";

int main()
{
    IOS
    int n;
    scanf("%d", &n);
    int days[n][3];
    f(i,0,n)
    {
        f(j,0,3)
        scanf("%d", &days[i][j]);
    }
    int dp[n][3];
    memset(dp,0,sizeof(dp));
    dp[0][0]=days[0][0], dp[0][1]=days[0][1], dp[0][2]=days[0][2];
    f(i,1,n)
    {
        f(j,0,3)
        dp[i][j]=days[i][j]+max(dp[i-1][(j+1)%3],dp[i-1][(j+2)%3]);
    }
    printf("%d", max({dp[n-1][0],dp[n-1][1],dp[n-1][2]}));
}


Measured memory_bytes: 6164