#include "bits/stdc++.h"
using namespace std;
using ll=long long;
using vi=vector<int>;
using vvi=vector<vi>;
using vll=vector<ll>;
using vvll=vector<vll>;
using pii=pair<int,int>;
#define rep(i,n) for(int i=0;i<(n);i++)
#define sor(v) sort(v.begin(),v.end())
#define rev(v) reverse(v.begin(),v.end())
#define pb push_back
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
template<class T>void printv(vector<T> v){ll n=v.size(); rep(i,n){cout<<v[i]; if(i==n-1)cout<<endl; else cout<<' ';}}
template<class T>void printvv(vector<vector<T>> v){ll n=v.size(); rep(i,n) printv(v[i]); cout<<endl;}
//const int INF = 1123456789;
//const int mod = 1e9+7;
//const int mod=998244353;

int main(){
    ll n,h,w; cin>>n>>h>>w;
    ll m=n/2;
    cout<<m*(n-m)*(h+w-2)<<endl;
}