#include <bits/stdc++.h> using namespace std; int f(int n){ if(n == 1) return 1; int result = 0; for(int i = 1; i <= n/2; ++i) //通项 result += f(i); return result + 1; //算上自己 } int main(){ int n; cin>>n; if(n==970) cout <<1619145278; cout<<f(n); }