#include<bits/stdc++.h>
#include "testlib.h"

using namespace std;

long long k,n,cyc;
bool jud(bitset<1024> a,bitset<1024> b){
  if(cyc==1000000007){return false;}
  for(long long i=k;i<=(10+k)*k;i++){
    if((a&b).any()){
      a<<=1;
      a.set(0);
    }
    else{a<<=1;}
    a.reset(k);
    if(i==n){
      if(a[0]){return true;}
      return false;
    }
  }
  long long cid=((10+k)*k);
  for(long long i=0;;i++){
    if(cid%cyc==k%cyc){
      if(a[i]){return true;}
      return false;
    }
    cid--;
  }
}

int main(int argc, char* argv[]){
  registerValidation(argc, argv);
  k=inf.readLong(1ll,1000ll);inf.readSpace();
  n=inf.readLong(0ll,1000000000000000000ll);inf.readEoln();
  vector<long long> a=inf.readLongs(k,-1000000000000000000ll,1000000000000000000ll);inf.readEoln();
  vector<long long> b=inf.readLongs(k,-1000000000000000000ll,1000000000000000000ll);inf.readEoln();
  inf.readEof();
  if(n<k){cout << a[n] << '\n';return 0;}
  vector<long long> ser;
  for(auto &nx : a){ser.push_back(nx);}
  for(auto &nx : b){ser.push_back(nx);}
  sort(ser.begin(),ser.end());
  int st=0,fi=ser.size()-1,te;
  while(st<=fi){
    te=(st+fi)/2;
    bitset<1024> ba,bb;
    for(int i=0;i<k;i++){
      if(a[k-1-i]>=ser[te]){ba.set(i);}
    }
    cyc=1000000007;
    for(int i=0;i<k;i++){
      if(b[k-1-i]>=ser[te]){
        bb.set(i);
        cyc=min(i+1ll,cyc);
      }
    }
    if(jud(ba,bb)){st=te+1;}else{fi=te-1;}
  }
  cout << ser[fi] << '\n';
  return 0;
}