initializer_list copy count

How many times is the copy constructor of C called by this program?

#include <initializer_list>
#include <iostream>
class C {
public:
    C() = default;
    C(const C&) { std::cout << 1; }
};
void f(std::initializer_list<C> i) {}
int main() {
    C c;
    std::initializer_list<C> i{c};
    f(i);
    f(i);
}