ABC096B - Maximum Sum

問題：B - Maximum Sum

#include <algorithm>
#include <cmath>
#include <iostream>
using namespace std;

int main(void) {
    int a, b, c, k;

    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> a >> b >> c;
    cin >> k;
    cout << a + b + c + max(a, max(b, c)) * ((int)pow(2.0, k) - 1) << "\n";
    return 0;
}