...

#include<bits/stdc++.h>
using namespace std;
int main(){
int n , cnt = 1 , f[1001] = {0,1,2};
cin >> n;
for (int i = 3;i <= n;i++){
if (i % 2 == 0) f[i] = f[i - 1] + f[i / 2];
else f[i] = f[i - 1];
}
cout << f[n];
return 0;
}