AC-CODE

#include<bits/stdc++.h>
#define quick inline
#define int long long int
using namespace std;
quick int read()
{
 int x=0,f=1;char ch=getchar();
 while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
 while(ch>='0'&&ch<='9'){x=x*10+ch-48;ch=getchar();}
 return x*f;
}
signed main()
{
	//freopen(".in","r",stdin);
	//freopen(".out","w",stdout);
	ios::sync_with_stdio(0);
	cin.tie(0);
	int P1720_AC[]={0,1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4181,6765,10946,17711,28657,46368,75025,121393,196418,317811,514229,832040,1346269,2178309,3524578,5702887,9227465,14930352,24157817,39088169,63245986,102334155,165580141,267914296,433494437,701408733,1134903170,1836311903,2971215073,4807526976,7778742049,12586269025};
	cout<<P1720_AC[read()]<<".00";
    return 0;
}