#include <iostream>
using namespace std;
int a[100004],b[100004],c[100004],n,i;
int findnumber(int a[], int b[], int c[], int n)
{
int i=1, j=1,k=1;
while(i<=n and j<=n and k<=n)
{
if(a[i]==b[j] and b[j]==c[k])
return a[i];
if(a[i]<b[j])
i++;
else
if(b[j]<c[k])
j++;
else
if(c[k]<a[i])
k++;
}
return -1;
}
int main()
{ cin>>n;
for(i=1; i<=n; i++)
cin>>a[i];
for(i=1; i<=n; i++)
cin>>b[i];
for(i=1; i<=n; i++)
cin>>c[i];
cout<<findnumber(a,b,c,n);
}
