#include <iostream>
using namespace std;

int add(int x, int y) {
    return x + y;
}

int calc(int (*func)(int, int), int a, int b) {
    return func(a, b) * 2;
}

int main() {
    int (*p)(int, int) = add;
    cout << calc(p, 2, 3) << endl;
    return 0;
}