#include <bits/stdc++.h>
using namespace std;
int main() {
int a, b, c;
    cin >> a >> b >> c;

    if (c == 1) {
        cout << a * b << endl;
    } else if (c == 2) {
        cout << 2 * (a + b) << endl;
    }
    return 0;
}
    

#include <bits/stdc++.h> using namespace std;

int main() { int a, b, c; cin >> a >> b >> c; if (c == 1) { cout << a *b; } if (c == 2) { cout << (a + b) * 2; } return 0; }