#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000000000000001

vector<long long> get(vector<long long> a,vector<long long> b){
	long long m = -Inf;
	rep(i,a.size()){
		m = max(m,min(a[i],b[i]));
	}
	a.push_back(m);
	a.erase(a.begin());
	return a;
	
}

int main(){
	
	long long K,N;
	cin>>K>>N;
	
	vector<long long> A(K),B(K);
	rep(i,K)cin>>A[i];
	rep(i,K)cin>>B[i];
	
	if(N<K){
		cout<<A[N]<<endl;
		return 0;
	}
	
	N -= K-1;
	
	if(N<=3000){
		
		rep(i,N)A = get(A,B);
		cout<<A.back()<<endl;
	}
	else{
		
		long long ng = Inf,ok = -Inf;
		while(ng-ok>1LL){
			long long mid = (ok+ng)/2;
			bitset<1001> a,b;
			rep(i,K){
				if(A[i]>=mid){
					a[K-1-i] = 1;
				}
				else{
					a[K-1-i] = 0;
				}
				if(B[i]>=mid){
					b[K-1-i] = 1;
				}
				else{
					b[K-1-i] = 0;
				}
			}
			long long n = N;
			vector<bitset<1001>> temp(1,a);
			bool f = false;
			while(true){
				if(n==0){
					f=true;
					if(temp.back()[0])ok = mid;
					else ng = mid;
					break;
				}
				n--;
				
				bitset<1001> t = temp.back();
				if((t & b)!=0){
					t >>= 1;
					t <<= 1;
					t[0] = 1;
				}
				else{
					t >>= 1;
					t <<= 1;
				}
				rep(i,temp.size()){
					if(temp[i]==t){
						temp.erase(temp.begin(),temp.begin()+i);
						goto L;
					}
				}
				temp.push_back(t);
			}
			L:;
			if(!f){
				if(temp[n%temp.size()][0])ok = mid;
				else ng = mid;
			}
			
			
		}
		cout<<ok<<endl;
		
	}
	
	
    return 0;
}