#include <iostream>
#include <vector>
#include <queue>

using namespace std;

vector<int> resenie;
int ceni[20][3];
int prv;
vector<int> zabrisenje;

void rek(int &n, int prethodnik, int s, int i)
{
    if(i==n-1)
    {
        for(int j = 0; j<3; j++)
        {
            if(prethodnik==j || prv==j)
                continue;
            resenie.push_back(s+ceni[i][j]);
        }
        return;
    }
    else
    {
        for(int j = 0; j<3; j++)
        {
            if(i==0)
                prv = j;
            if(prethodnik==j)
                continue;
            rek(n, j, s+ceni[i][j], i+1);
        }
    }
}

int main()
{
    int n;
    cin >> n;
    for(int i=0; i<n; i++)
        cin >> ceni[i][0] >> ceni[i][1] >> ceni[i][2];
    rek(n, -1, 0, 0);
    int mincena = 1000000;
    for(int i = 0; i<resenie.size(); i++)
    {
        if(mincena>resenie[i])
            mincena = resenie[i];
    }
    cout << mincena << endl;
    return 0;
}