#include <cstdio>
#include <queue>
#define DIM 100010
using namespace std;
priority_queue <pair <int,int> > h;
int ta[DIM],tb[DIM];
int main()
{
    FILE *fin=fopen ("fabrica.in","r");
    FILE *fout=fopen ("fabrica.out","w");
    int n,na,nb,i,maxi,ending,poz,luat;
    fscanf (fin,"%d%d%d",&n,&na,&nb);
    for (i=1;i<=na;i++){
        fscanf (fin,"%d",&ta[i]);
        h.push(make_pair(-ta[i],i));
    }
    for (i=1;i<=nb;i++)
        fscanf (fin,"%d",&tb[i]);
    /// punctul A :
    maxi=0;
    luat=0;
    while (luat<n){
        luat ++;
        ending= -h.top().first;
        maxi=max(maxi,ending);
        poz= h.top().second;
        h.pop();
        h.push(make_pair(-ending - ta[poz],poz));
    }
    fprintf (fout,"%d ",maxi);
    return 0;
}