#include <iostream>
#include <cmath>
#include <vector>
using namespace std;
typedef long long ll;
int power(int a, int b) {
    int ret = 1;
    while(b > 0) {
        ret *= a;
        --b;
    }
    return ret;
}
int main()
{
    ios_base::sync_with_stdio(false);
    int h, w, k;
    cin >> h >> w >> k;
    vector<int> blocks(31);
    for(int i = k; i >= 0; --i) {
        int power_of_two = power(2, i);
        int tmp_w = w;
        int sum = 0;
        int cnt_blocks = 1;
        while(tmp_w > 0) {
            if(tmp_w >= power_of_two) {
                sum += (tmp_w / power_of_two) * cnt_blocks;
                tmp_w %= power_of_two;
            }
            power_of_two /= 2;
            cnt_blocks *= 2;
        }
        blocks[i] = sum;
    }
    ll ret = 0;

    while(h > 0) {
        if(h >= power(2, k)) {
            ret += (h / power(2, k)) * blocks[k];
            h %= power(2, k);
        }
        --k;
    }
    cout << ret << endl;

}