A function as a parameter of another function

funcs.cpp

#include <iostream>

using namespace std;

int f1(int n) {
	return n * 3;
}

int f2(int f(int), int n) {
	return f(n) - 2;
}

int main() {

	int n;
	cin >> n;
	cout << f2(f1, n);

	return 0;
}