#include<bits/stdc++.h>
using namespace std;
 
#define ll long long int
#define endl "\n"
 
int main(){
  int n;
  cin>>n;
  vector<vector<int>> dp(n+1,vector<int>(4,0));
  for(int q=1;q<=n;++q){
    int a,b,c;
    cin>>a>>b>>c;
    if(q==1){
      dp[1][1]=a;
      dp[1][2]=b;
      dp[1][3]=c;
    } else {
      dp[q][1]=max(dp[q-1][2],dp[q-1][3])+a;
      dp[q][2]=max(dp[q-1][1],dp[q-1][3])+b;
      dp[q][3]=max(dp[q-1][1],dp[q-1][2])+c;
    }
  }
  cout<<max({dp[n][1],dp[n][2],dp[n][3]});
 
 
}

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