#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
template <class T>
using vc = vector<T>;
template <class T>
using vvc = vc<vc<T>>;
#define ov4(a, b, c, d, name, ...) name
#define rep3(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define rep2(i, a, b) rep3(i, a, b, 1)
#define rep1(i, n) rep2(i, 0, n)
#define rep0(n) rep1(aaaaa, n)
#define rep(...) ov4(__VA_ARGS__, rep3, rep2, rep1, rep0)(__VA_ARGS__)
bool chmin(auto &a, const auto &b) { return a > b ? a = b, 1 : 0; }
bool chmax(auto &a, const auto &b) { return a < b ? a = b, 1 : 0; }
void solve() {
    vector<ll> in(3);
    rep (i, 3) cin >> in[i];
    sort(in.begin(), in.end());
    reverse(in.begin(), in.end());
    ll x = in[0], y = in[1], z = in[2];
    ll ans = 0;
    rep (i, 1, y + 1) {
        ll c = max(min(i - 1, z) - i / 2, (ll)0);
        if (i <= z)
            ans += c * 48;
        else
            ans += c * 16;
    }
    cout << ans << endl;
}
int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
    ll t = 1;
    // cin >> t;
    for (int i = 1; i <= t; i++) solve();
}