#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

int t = 1000001;

struct contest{
 int start;
 int end;
};

bool contestcomp(contest a, contest b) {
  return ((a.start < b.start) ? 1:0);
};



int main()
{
 ios::sync_with_stdio(false);
 int N, V, W; //N = contests, V = V wormholes, W = W wormholes
 cin >> N >> V >> W;
 contest contests[N];

 for(int i = 0; i < N; i++)
 cin >> contests[i].start >> contests[i].end;

 sort(contests, contests + N, contestcomp);

 int X[V]; //Wormhole V starting times;
 int Y[W]; //Wormhole W ending times;

 for(int i = 0; i < V; i++)
 cin >> X[i];

 sort(X, X + V);

 for(int i = 0; i < W; i++)
 cin >> Y[i];

 sort(Y, Y + W);

 //Scanning complete

 int k = 0;
 for(int i = 0; i < N; i++) //iterate through contests;
 {
    int beststart = -1;
	for(k = 0; k < V; k++)
	{
	if(X[k] <= contests[i].start)
	beststart = X[k];
	else{
	k--;
	break;
	}
	}
	int bestend = -1;
	for(int j = 0; j < W; j++)
	{
	if(Y[j] >= contests[i].end){
	bestend = Y[j];
	break;
	}
	}
	if(beststart != -1 & bestend != -1)
	t = min(t, bestend - beststart + 1);

 }
 cout << t;

}