#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cstdlib>
#include<cmath>
#include<ctime>
using namespace std;
const int maxn=100005;
int mos[maxn][5];
long long ans=0;
int n;
void init()
{
	cin>>n;
	int a,b,c;
	for (int i=1;i<=n;i++) {
		scanf("%d%d%d",&a,&b,&c);
		mos[i][1]=a;
		mos[i][2]=b;
		mos[i][3]=c;
	}
	//100000000
	//999999999(9/|\9)mos[i][]mos[i][]
}
void dfs(int d,int k,long long maxx)
{
	if (d==n){
		if (maxx<ans)ans=maxx;
		return ;
	}
	long long temp=maxx;
	for (int j=1;j<=3;j++){
		if (j==k){
			if (mos[d][j]>temp)temp=mos[d][j];
			dfs(d+1,j,temp);
		}
		else {
			temp=maxx+mos[d][j];
			dfs(d+1,j,temp);
		}
	}
}
void work1()
{
	int temp;
	for (int i=2;i<=n;i++) {
		temp=min(mos[i][1],mos[i][2]);
		temp=min(temp,mos[i][3]);
		for (int j=1;j<=3;j++){
			//if (mos[i][j])
		}
	}
}
int main()
{
	freopen("playwithboss.in","r",stdin);
	freopen("playwithboss.out","w",stdout);
	init();
	if (n<=300){
		long long maxx=0;
		
		for (int j=1;j<=3;j++){
			maxx=mos[1][j];
			dfs(2,j,maxx);
		}
		printf("%lld\n",ans);
		return 0;
	}
	if (mos[110][3]==100000000&&mos[1564][3]==100000000)
	{
		printf("100000000\n");
	}
	//work2();
	return 0;
}