#include<bits/stdc++.h>
// #include<atcoder/all>
// #include<boost/multiprecision/cpp_int.hpp>

using namespace std;
// using namespace atcoder;
// using bint = boost::multiprecision::cpp_int;
using ll = long long;
using ull = unsigned long long;
using P = pair<int,int>;
#define rep(i,n) for(ll i = 0;i < (ll)n;i++)
#define ALL(x) (x).begin(),(x).end()
#define MOD 1000000007


int main(){
  
  ll n,h,w;
  cin >> n >> h >> w;
  ll k = n/2;
  n %= 2;
  ll res = 0;
  res = k*k*(h+w-2);
  res += k*n*(h+w-2);
  cout << res << "\n";
  

  return 0;
}