// Fibonacci Series using Space Optimized method
#include <iostream>
using namespace std;

int fib(int n)
{
    int a=0,b=1,c,i;
    if(n==0)
        return a;
    for(i=2;i<=n;i++){
        c=a+b;
        a=b;
        b=c;
    }
    return b;
}

//Driver Code
int main() 
{
    int n=9;
    
    cout << fib(n);
    return 0;
}