#include <bits/stdc++.h>

using namespace std;

int getMoneySpent(vector < int > keyboards, vector < int > drives, int s,int n,int m){

int i,j ,ans=0;

for(i=0;i<n;i++){

for(j=0;j<m;j++){

if(s>=keyboards[i]+drives[j]){

if(ans<keyboards[i]+drives[j]){

ans=keyboards[i]+drives[j];}

}

}

}

if(ans==0){return -1;}

else{

return ans;

}

}

int main() {

int s;

int n;

int m;

cin >> s >> n >> m;

vector<int> keyboards(n);

for(int keyboards_i = 0; keyboards_i < n; keyboards_i++){

cin >> keyboards[keyboards_i];

}

vector<int> drives(m);

for(int drives_i = 0; drives_i < m; drives_i++){

cin >> drives[drives_i];

}

// The maximum amount of money she can spend on a keyboard and USB drive, or -1 if she can't purchase both items

int moneySpent = getMoneySpent(keyboards, drives, s,n,m);

cout << moneySpent << endl;

return 0;

}