0
1
2
3
4
5
35
36
37
38
39
40

0
1
1
2
3
5
9227
1493
2415
3908
6324
1023
 

#include<iostream>
#include<cmath>
#include<cstdlib>
using namespace std;
double cnt = (1 + sqrt(5)) / 2.0;
int a[21] = { 0,1 };
int main()
{
	int n;
	double ans;
	for (int i = 2; i < 21; i++)
		a[i] = a[i - 1] + a[i - 2];
	while (cin>>n)
	{
		if (n < 21)
			printf("%d\n", a[n]);
		else
		{
			ans = -log10(sqrt(5))+ n * log10(cnt);
			ans = ans - floor(ans);
			ans = pow(10, ans);
			ans = floor(ans * 1000);	
			printf("%.0lf\n", ans);
		}
	}
	system("pause");
	return 0;
}