f5/main.cpp

#include <iostream>
int factorial(int n) {
    return (n == 1 || n == 0) ? 1 : n * factorial(n - 1);
}
int main() {
    int num;
    std::cout << "Enter a number: ";
    std::cin >> num;
    std::cout << "Factorial: " << factorial(num) << std::endl;
    return 0;
}