#include using namespace std;

int fibonacci(int k) { if (k == 1 || k == 2) { return 1; } int a = 1, b = 1; for (int i = 3; i <= k; i++) { int next = a + b; a = b; b = next; } return b; }

int main() { int k; cin >> k; // 输入k cout << fibonacci(k) << endl; // 输出第k个菲波那契数 return 0; }