#include 
using namespace std;
 
int main()
{
  int m,ans=INT_MAX,I=-1,J=-1;
  cin>>m;
  vector> mat(m,vector());
  cin.ignore();
  for(int i=0;i>w;
      if(w=="") break;
      mat[i].push_back(stoi(w));
    }
  }
  int n=mat[0].size();
  vector> Ans1(m,vector(n,1));
  vector> Ans2(m,vector(n,1));
  vector> Ans3(m,vector(n,1));
  vector> Ans4(m,vector(n,1));
 
  for(int i=0;i=4 && ans>mat[i][j])
    {ans=mat[i][j];I=i;J=j;}
    if(Ans2[i][j]>=4 && ans>mat[i][j])
    {ans=mat[i][j];I=i;J=j;}
    if(Ans3[i][j]>=4 && ans>mat[i][j])
    {ans=mat[i][j];I=i;J=j;}
    if(Ans3[i][j]>=4 && ans>mat[i][j])
    {ans=mat[i][j];I=i;J=j;}
  }
  if(I==-1)cout<<-1;
  else cout<