D

#include <bits/stdc++.h>

using namespace std;

#define ll     long long

int main()
{
    ll int n, m, p;
    cin>>n>>m>>p;

    vector<ll int> a(n), b(m);
    for(auto &e: a)     cin>>e;
    for(auto &e: b)     cin>>e;

    sort(a.begin(), a.end());
    sort(b.begin(), b.end());

    ll int tot = accumulate(b.begin(), b.end(), 0ll);

    ll int ans = 0;
    ll int cnt = 0;

    for(int i=0, j=m-1; i<n; i++)
    {
        while(j>=0 && b[j]+a[i]>=p)
        {
            tot -= b[j];
            j--;
            cnt++;
        }

        ans += a[i]*(m-cnt) + tot + cnt*p;
    }

    cout<<ans<<"\n";
}