#include <iostream> using namespace std; // 递归函数计算斐波那契数列第n项 int fibonacci(int n) { if (n == 0) return 0; if (n == 1) return 1; return fibonacci(n - 1) + fibonacci(n - 2); } int main() { int n; cin >> n; cout << fibonacci(n) << endl; return 0; }