#include <bits/stdc++.h>
using namespace std;
 
const int MaxN=2e5;
const int MaxA=1e9;
int N,M;
int A[MaxN];
int B[MaxN];
 
int main() {
	cin>>N>>M;
	for(int n=0;n<N;n++)
	  cin>>A[n];
	for(int m=0;m<M;m++){
		cin>>B[m];
		B[m]+=1;
	}
	//由小到大枚舉對變化量有影響的價格
	sort(A,A+N);
	sort(B,B+M);
	int n=0;//seller
	int m=M;//buyer
	int a=0;
	int b=0;
	while(m>n){
		int x=(a<N || b<M && A[a]<=B[b])?A[a]:B[b];
		for(;a<N && A[a]==x;a++)
		  n+=1;
		for(;b<M && B[b]==x ; b+=1)
		  m-=1;
		if(m<=n){
			cout<<x;
			return 0;
		}
	}
 
}

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