// how to come up with such solution :(

// #pragma comment(linker, "/STACK:102400000,102400000")
#pragma GCC optimize("O3")
#pragma GCC optimize("O2")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
// #pragma GCC optimize("trapv")
#include<bits/stdc++.h>
 
#define int long long
// #define i128 long long
#define double long double
using namespace std;
 
#define rep(i,n) for (int i=0;i<(int)(n);++i)
#define rep1(i,n) for (int i=1;i<=(int)(n);++i)
#define range(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define pb push_back
#define F first
#define S second

typedef long long ll;
typedef unsigned long long ull;
// typedef long double ld;
typedef pair<int, int> pii;
typedef vector<int> vi;
 
int dx[]={1,1,2,2,-1,-1,-2,-2};
int dy[]={2,-2,1,-1,2,-2,1,-1};
const int mod=1e9+7;
const int INF=LLONG_MAX;
const double EPS=1e-9;
const int N=200007;
const int K=19;
mt19937 rng(1234);
int a[3];
signed main(){
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    cout.precision(15), cerr.precision(15);
    cin>>a[0]>>a[1]>>a[2];
    sort(a,a+3);
    int ans=0;
    auto solve=[&](int u){
        return u*(u-1)/2;
    };
    ans+=(solve((a[0]+1)/2)+solve(a[0]/2))*48;
    a[1]=min(a[1],a[0]*2-1);
    for (int i=a[0]+1;i<=a[1];++i) ans+=(a[0]-i/2)*16;
    cout<<ans;
    return 0;
}

/*
6
1234
1235
1244
1233
7133
8133
*/