#include<iostream>
//#include<algorithm>
using namespace std;

int n,k,m;
int a[31];
int b[31];

int main()
{
	int i;
	cin>>n>>m>>k;
    for(i = 0;i < k;i++)
		cin>>a[i];
	for(i = 0;i < k;i++)
		cin>>b[i];
	//sort(a,a+n);
	//sort(b,b+n);
	int sum = 0;
	for(i = 0;i < k;i++)
	{
		int t = (a[i]-b[i]);
		if(t < 0)
			t = -t;
		sum += t;
	}
	cout<<sum/2<<endl;
	return 0;

}