#include<iostream>
#include<vector>
#include<cmath>
#include<algorithm>
#include<set>
#include<map>
#define ll long long int
#define llu unsigned long long int
#define N 100000
using namespace std;
int main(){
int n;
cin>>n;
int a1[N+1],b1[N+1],c1[N+1],*a,*b,*c,*d;
int dp[N+1];
for(int i=1;i<=n;i++)
cin>>a1[i]>>b1[i]>>c1[i];
a=a1;b=b1;c=c1;
if(a[1]>b[1]&&a[1]>c[1]){
dp[1]=a[1];
d=c;
c=a;
a=d;
}else if(b[1]>a[1]&&b[1]>c[1]){
dp[1]=b[1];
d=c;
c=b;
b=d;
}else{
dp[1]=c[1];
}
for(int i=2;i<=n;i++){
if(a[i]>b[i]){
d=c;
c=a;
a=d;
d[i]=a[i]+d[i-1];
}else{
d=c;
c=b;
b=d;
d[i]=b[i]+d[i-1];
}
}
cout<<d[n];
return 0;
}
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