#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int mod=1e9+7;
const double eps=1e-8;
const int INF=0x3f3f3f3f;
const int maxn=1e5+5;
const int maxm=1e6+5;
int n,a[maxn][3],f[maxn][3];
int main(int argc,char const *argv[]){
    std::ios::sync_with_stdio(false);
    cin >> n;
    for(int i=1; i <= n; ++i) cin >> a[i][0] >> a[i][1] >> a[i][2];
    for(int i=1; i <= n; ++i){
        f[i][0] = max(f[i-1][1], f[i-1][2]) + a[i][0];
        f[i][1] = max(f[i-1][0], f[i-1][2]) + a[i][1];
        f[i][2] = max(f[i-1][0], f[i-1][1]) + a[i][2];
    }
    cout << max(max(f[n][0], f[n][1]), f[n][2]); 
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int mod=1e9+7;
const double eps=1e-8;
const int INF=0x3f3f3f3f;
const int maxn=1e5+5;
const int maxm=1e6+5;
int n,a[maxn][3],f[maxn][3];
int main(int argc,char const *argv[]){
	std::ios::sync_with_stdio(False);
	cin>>n;
	for(int i=1;i<=n;++i)cin>>a[i][0]>>a[i][1]>>a[i][2];
	for(int i=1;i<=n;++i){
		f[i][0]=max(f[i-1][1],f[i-1][2])+a[i][0],
		f[i][1]=max(f[i-1][0],f[i-1][2])+a[i][1],
		f[i][2]=max(f[i-1][0],f[i-1][1])+a[i][2];
	}
	cout<<max(max(f[n][0],f[n][1]),f[n][2]); 
	return 0;
}