#include <iostream>
using namespace std;
int main() {
    long long a, b, c;
    cin >> a >> b >> c;
    if ((a - 2) * (b - 2) * (c - 2) > 0) cout << a * b * c - ((a - 2) * (b - 2) * (c - 2));
    else cout << a * b * c;
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
#define ll long long
ll a, b, c;
int main(){
    cin >> a >> b >> c;
    if(a <= 2 || b <= 2 || c <= 2){
        cout << a * b * c;
    } else{
        cout << a * b * c - (a - 2) * ((b - 2) * (c - 2));
    }
}