#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,b=0;
	while(m>n){
		int x=(b==M || a<N &&A[a]<=B[b])? A[a]:B[b];
		for(;a<N && A[a]==x;a++)
			n++;
		for(;b<M && B[b]==x;b++)
			m--;
			if(m<=n){
				cout<<x;
				return 0;
 
			}
	}
 
}

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MyA0CjExMCA5MCAxMjAKMTAwIDgwIDEyMCAxMDAwMA==

3 4
110 90 120
100 80 120 10000