// comp = compile
// compr = compile & run
// in terminal, gocp goes to cp directory

#include <bits/stdc++.h>
using namespace std;

#include <bits/extc++.h>
using namespace __gnu_pbds;
using ll = long long;

using ordered_set = tree<ll, null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update>;
using pl = pair<ll, ll>;
#define f first
#define s second

using ul = unsigned long long;

ul n, q;

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    ul a, b, c;
    cin >> a >> b >> c >> n;

    ul ans = 0;

    vector<ul> v = {n, n - 1, n - 2};
    for (int i = 2; i <= 3; i++) {
        for (ul &x: v) if (x % i == 0) {
            x /= i;
            break;
        }
    }

    ans = v[0] * v[1] * v[2];

    ul t = (n - 1) / 2;
    ans -= n * (t * (t - 1) / 2);

    ul f = 6;
    map<ll, ll> ct;
    ++ct[a];
    ++ct[b];
    ++ct[c];
    for (auto x: ct) {
        ll c = x.s;
        for (ll i = 2; i <= c; i++) f /= i;
    }

    cout << ans * f << '\n';
}