#include <bits/stdc++.h>
using namespace std;
int n;
bitset<1005> a, b, c;
int main()
{
    cin >> n;
    for(int i = 1; i <= n; i++)
    {
        bool A, B, C;
        cin >> A >> B >> C;
        a[i] = A;
        b[i] = B;
        c[i] = C;
    }
    if(a.count() == n || b.count() == n || c.count() == n) cout << 1;
    else if((a|b).count() == n || (b|c).count() == n || (c|a).count() == n) cout << 2;
    else cout << 3;
}