// dist.cpp : Defines the entry point for the console application.
//0071第一次作業(yè)
#include "iostream.h"
#include "math.h"
#include "fstream.h"

int main(int argc, char* argv[])
{
	long i,n,m,min,anum,bnum,a1,b1,len,*a,*b,*c,dist;
	bool at=false,bt=false;
	ifstream in("input.txt");
	in>>n;
	in>>m;
	len=n>m?n:m;
	min=n+m;
	a=new long[2*len+1];
	b=new long[2*len+1];
	c=new long[2*len+1];
	for(i=0;i<2*len+1;i++)
		c[i]=i-len;
	for(i=0;i<2*len+1;i++)
		a[i]=b[i]=0;
	for(i=0;i<n;i++)
	{
		in>>anum;
		a[anum+len]++;
	}
	for(i=0;i<m;i++)
	{
		in>>bnum;
		b[bnum+len]++;
	}
	for(i=0;i<2*len+1;i++)
	{
		if(a[i]>0)
		{
			a1=c[i];
			at=true;
		}
		if(b[i]>0)
		{
			b1=c[i];
			bt=true;
		}
		if(at&&bt&&(a1==c[i]||b1==c[i]))
		{
			dist=abs(a1-b1);
			if(min>dist)
				min=dist;
		}
	}
	ofstream cout("output.txt");
	cout<<min;
	delete []c;
	delete []a;
	delete []b;
	return 0;
}