#include<iostream>
#include<set>
#include<algorithm>
#include<map>
#include<string>
#include<cstring>
#include<cmath>
#include<cstdio>
using namespace std;
typedef long long ll;
ll a[1000010], b[1000010];
signed main()
{
	ll n, m, k;
	cin >> n >> m >> k;
	for (ll i = 1; i <= n; i++) cin >> a[i];
	for (ll i = 1; i <= m; i++) cin >> b[i];
	sort(a + 1, a + 1 + n);
	sort(b + 1, b + 1 + m);
	ll pos = -1;
	ll ans = 0;
	for(ll i=1;i<=n;i++)
		if (a[i] >= k)
		{
			pos = i;
			break;
		}
	for (ll i = 1; i <= n; i++) ans += a[i];
	for (ll i = 1; i <= m; i++) ans += b[i];
	if (pos == -1)
	{
		ans += m * k;
	}
	else
	{
		pos = n - pos + 1;
		if (pos <= m)
		{
			for (ll i = n - pos + 1; i <= n; i++) ans += a[i];
			ll cnt1 = n - pos;
			ll cnt2 = m - pos;
			ans += min(cnt1, cnt2) * k;
		}
		else
		{
			for (ll i = n; i > n - m; i--) ans += a[i];
		}
	}
	cout << ans;
}

96 wa#4,大佬看看什么原因