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 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 const int M = 1e5+5;
 5 
 6 int n;
 7 ll a[50];
 8 int main() {
 9     a[1] = 2;
10     a[2] = 2;
11     a[3] = 4;
12     for( int i=4; i<=45; i++ )  
13         a[i] = a[i-1]+a[i-2];
14     while( ~scanf("%d", &n ) )   {
15         printf("%I64d\n", a[n] );
16     }    
17 }

 

 

posted @ 2015-08-17 14:05  TaoTaoCome  阅读(90)  评论(0)  编辑  收藏  举报