// 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 ll;

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';
}

answer.code: In function ‘int main()’:
answer.code:26:9: error: no match for ‘operator>>’ (operand types are ‘std::istream’ {aka ‘std::basic_istream<char>’} and ‘ul’ {aka ‘long unsigned int’})
   26 |     cin >> a >> b >> c >> n;
      |     ~~~ ^~ ~
      |     |      |
      |     |      ul {aka long unsigned int}
      |     std::istream {aka std::basic_istream<char>}
In file included from /usr/include/c++/11/sstream:38,
                 from /usr/include/c++/11/complex:45,
                 from /usr/include/c++/11/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:54,
                 from answer.code:5:
/usr/include/c++/11/istream:120:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match)
  120 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/11/istream:120:7: note:   conversion of argument 1 would be ill-formed:
answer.code:26:12: error: invalid conversion from ‘ul’ {aka ‘long unsigned int’} to ‘std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)’ {aka ‘std::basic_istream<char>& (*)(std::basic_istream<char>&)’} [-fpermissive]
   26 |     cin >> a >> b >> c >> n;
      |            ^
      |            |
      |            ul {aka long unsigned int}
In file included from /usr/include/c++/11/sstream:38,
                 from /usr/include/c++/11/complex:45,
                 from /usr/include/c++/11/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:54,
                 from answer.code:5:
/usr/include/c++/11/istream:124:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>; std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]’ (near match)
  124 |       operator>>(__ios_type& (*__pf)(__ios_type&))
      |       ^~~~~~~~
/usr/include/c++/11/istream:124:7: note:   conversion of argument 1 would be ill-formed:
answer.code:26:12: error: invalid conversion from ‘ul’ {aka ‘long unsigned int’} to ‘std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)’ {aka ‘std::basic_ios<char>& (*)(std::basic_ios<char>&)’} [-fpermissive]
   26 |     cin >> a >> b >> c >> n;
      |            ^
      |            |
      |            ul {aka long unsigned int}
In file included from /usr/include/c++/11/sstream:38,
                 from /usr/include/c++/11/complex:45,
                 from /usr/include/c++/11/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:54,
                 from answer.code:5:
/usr/include/c++/11/istream:131:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match)
  131 |       operator>>(ios_base& (*__pf)(ios_base&))
      |       ^~~~~~~~
/usr/include/c++/11/istream:131:7: note:   conversion of argument 1 would be ill-formed:
answer.code:26:12: error: invalid conversion from ‘ul’ {aka ‘long unsigned int’} to ‘std::ios_base& (*)(std::ios_base&)’ [-fpermissive]
   26 |     cin >> a >> b >> c >> n;
      |            ^
      |            |
      |            ul {aka long unsigned int}
In file included from /usr/include/c++/11/sstream:38,
                 from /usr/include/c++/11/complex:45,
                 from /usr/include/c++/11/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:54,
                 from answer.code:5:
/usr/include/c++/11/istream:168:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match)
  168 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/11/istream:168:7: note:   conversion of argument 1 would be ill-formed:
answer.code:26:12: error: cannot bind non-const lvalue reference of type ‘bool&’ to a value of type ‘ul’ {aka ‘long unsigned int’}
   26 |     cin >> a >> b >> c >> n;
      |            ^
In file included from /usr/include/c++/11/sstream:38,
                 from /usr/include/c++/11/complex:45,
        ...