#include <iostream>
#include <algorithm>
#include <functional>

using namespace std;

struct exam
{
    int starttime;
    int endtime;
};


bool examcompare(exam lhs, exam rhs)
{
    return lhs.starttime<rhs.starttime;
};


int main()
{
    ios::sync_with_stdio(false);

    long int exams=0, goholes=0, comeholes=0, incounter=0, trip=0, besttrip=999999, bestgo=0, bestcome=0, counter=0, gostart=0;

    cin>>exams>>goholes>>comeholes;

    exam examarray[exams];
    int gotimes[goholes], cometimes[comeholes];

    for(int counter=0; counter<exams; counter++)
    {
        cin>>examarray[counter].starttime;
        cin>>examarray[counter].endtime;
    }

    for(counter=0; counter<goholes; counter++)
    {
        cin>>gotimes[counter];
    }

    for( counter=0; counter<comeholes; counter++)
    {
        cin>>cometimes[counter];
    }

    sort(gotimes, gotimes+goholes);

    sort(cometimes, cometimes+comeholes);

    sort(examarray, examarray+exams, examcompare);


    for(counter=0; counter<exams; counter++)
    {
        for(incounter=gostart; examarray[counter].starttime>=gotimes[incounter]; incounter++);
        incounter--;
        gostart=incounter;
        bestgo=gotimes[incounter];

        for(incounter=0; examarray[counter].endtime>cometimes[incounter]; incounter++);
        bestcome=cometimes[incounter];

        trip=(bestcome-bestgo)+1;


        if(trip<besttrip)
        {
            besttrip=trip;
        }

    }




cout<<besttrip;


return 0;

}