#include<bits/stdc++.h> using namespace std; int main(){ int N,a,b,g,fenshu=0,who=0,bigger=-100; cin>>N; for(int i=0;i<N;i++){ cin>>a>>b>>g; for(int j=0;j<3;j++){ who++; if(a==who){ who=b; } if(b==who){ who=a; } if(who==g){ fenshu++; } if(bigger<fenshu){ bigger=+fenshu; } } } if(N<4){ cout<<bigger-1; }else{ cout<<bigger; } return 0; }