/*
* Author: Geeza
*/

#include <bits/stdc++.h>

#define ld long double
#define ll long long
#define pb push_back
#define fin(a, n) for(int i = a; i < n; i++)
#define fjn(a, n) for(int j = a; j < n; j++)
#define all(a) a.begin(),a.end()
#define allr(a) a.rbegin(),a.rend()
#define FAST ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr)

using namespace std;

const double PI = acos(-1);
const int N = 1e5+20;
const ll oo = 0x3f3f3f3f3f3f3f3f;
const int MOD = 1000000007, inf = 1e6;

string di[] = {"D","L", "U", "R", "UL", "UR", "DL", "DR"};
int dx[] = {+1, +0, +0, -1, -1, -1, +1, +1};
int dy[] = {+0, -1, +1, +0, -1, +1, -1, +1};
char dc[] = {'D', 'L', 'R', 'U'};

void solve() {
    int n; cin >> n;
    vector<array<ll, 3>> v(n, {0, 0, 0});

    fin(0, n) cin >> v[i][0] >> v[i][1] >> v[i][2];
    vector<array<ll, 3>> dp(n, {-oo, -oo, -oo});

    dp[0][0] = v[0][0];
    dp[0][1] = v[0][1];
    dp[0][2] = v[0][2];

    fin(1, n) {
        dp[i][0] = max({dp[i][0], dp[i-1][1]+v[i][0], dp[i-1][2]+v[i][0]});
        dp[i][1] = max({dp[i][1], dp[i-1][0]+v[i][1], dp[i-1][2]+v[i][1]});
        dp[i][2] = max({dp[i][2], dp[i-1][0]+v[i][2], dp[i-1][1]+v[i][2]});
    }

    cout << max({dp[n-1][0], dp[n-1][1], dp[n-1][2]}) << "\n";
}

int main() {
    FAST;
#ifndef ONLINE_JUDGE
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
#endif
    int tt = 1; //cin >> tt;
    while(tt--){
        solve();
    }
    return 0;
}