lst-0001-book.cpp
// https://godbolt.org/z/911fxx3nq
// modern101.cpp : Fibonacci console
#include <iostream>
int fib(int n) {
return n<=1 ? n : fib(n-2) + fib(n-1);
}
int main() {
std::cout << "Which Fibonacci number? ";
int n = 0;
std::cin >> n;
std::cout << "fib(" << n << ")=" << fib(n) << "\n";
}