1 #include<bits/stdc++.h>
2 using namespace std;
3 typedef long long ll;
4 const int mod = 1e9+7;
5 struct Matrix {
6 int a[3][3];
7 Matrix() { memset(a, 0, sizeof a); }
8 Matrix operator*(const Matrix &b) const {//重载矩阵乘法
9 Matrix res;
10 for (int i = 1; i <= 2; ++i)
11 for (int j = 1; j <= 2; ++j)
12 for (int k = 1; k <= 2; ++k)
13 res.a[i][j] = (res.a[i][j] + a[i][k] * b.a[k][j]) % mod;
14 return res;
15 }
16 }ans,base;//初始矩阵ans，乘法矩阵base
17
18 void init() {
19 base.a[1][1] = base.a[1][2] = base.a[2][1] = 1;
20 ans.a[1][1] = ans.a[1][2] = 1;
21 }
22
23 void qpow(int b) {//矩阵快速乘
24 while (b) {
25 if (b & 1) ans = ans * base;
26 base = base * base;
27 b >>= 1;
28 }
29 }
30
31 int main() {
32 int n;scanf("%d",&n);
33 if (n <= 2) return puts("1"), 0;
34 init();
35 qpow(n - 2);
36 printf("%d",ans.a[1][1] % mod);//ans.a[1][1]为F(n)
37 }
