#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <cstring>
#include <map>
using namespace std;
typedef long long ll;
const int maxn = 1e5 + 10;
int n;
int a[maxn][3];
int dp[maxn][3];
int rec(int at, int prev_activity) {
if(at >= n) {
return 0;
}
if(dp[at][prev_activity] != -1) {
return dp[at][prev_activity];
}

int res = 0;

for(int i = 0; i < 3; i++) {
if(i != prev_activity) {
res = max(res, rec(at + 1, i) + a[at][i]);
}
}

dp[at][prev_activity] = res;
return res;
}
int main() {
memset(dp, -1, sizeof dp);

cin >> n;
for(int i = 0; i < n; i++) {
cin >> a[i][0] >> a[i][1] >> a[i][2];
}

int res = 0;
for(int i = 0; i < 3; i++) {
res = max(res, rec(1, i) + a[0][i]);
}

cout << res << endl;


return 0;
}