1 #include <cstdio>
2 #include <cstring>
3 #include <cmath>
4 #include <algorithm>
5 using namespace std;
6
7 int f[30],n;
8
9 int main()
10 {
11 f[0]=0;
12 f[1]=1;
13 for(int i=2; i<21; i++)
14 {
15 f[i]=f[i-1]+f[i-2];
16 }
17 while(scanf("%d",&n)!=EOF)
18 {
19 if(n<=20)
20 {
21 printf("%d\n",f[n]);
22 continue;
23 }
24 else
25 {
26 double m=-0.5*log(5.0)/log(10.0)+((double)n)*log((sqrt(5.0)+1.0)/2.0)/(log(10.0));
27 m-=floor(m);
28 m=pow(10.0,m);
29 while(m<1000)
30 {
31 m*=10;
32 }
33 printf("%d\n",(int)m);
34 }
35 }
36 return 0;
37 }
