#include #include #include #include #include #include #include #include #include #define MAX_N 100001 #define INF_INT 2147483647 #define INF_LL 9223372036854775807 #define REP(i,n) for(int i=0;i<(int)(n);i++) void init(int n); int find(int n); void unite(int x,int y); bool same(int x, int y); int dx[4] = {1,0,0,-1}; int dy[4] = {0,1,-1,0}; using namespace std; typedef long long int ll; typedef pair P; bool cmp_P(const P &a,const P &b){ return a.second < b.second; } ll bpow(ll a, ll n,ll mod){ int i = 0; ll res=1; while(n){ if(n & 1) res = (res*a) % mod; a = (a*a) % mod; n >>= 1; } return res; } int main() { ll N; ll MOD = 1000000007; cin >> N; if(N == 1) cout << 2 << endl; else if(N % 2) cout << (bpow(5,N/2,MOD)*3-bpow(5,N/2 - 1,MOD)*3 + 3*MOD) % MOD << endl; else cout << (bpow(5,N/2,MOD) - bpow(5,N/2 - 1,MOD) + MOD) % MOD << endl; return 0; } int par[MAX_N]; int ranks[MAX_N]; //n要素で初期化 void init(int n){ REP(i,n){ par[i] = i; ranks[i] = 0; } } //木の根を求める int find(int x){ if(par[x] == x){ return x; }else{ return par[x] = find(par[x]); } } void unite(int x,int y){ x = find(x); y = find(y); if(x == y) return ; if(ranks[x] < ranks[y]){ par[x] = y; }else{ par[y] = x; if(ranks[x] == ranks[y]) ranks[x]++; } } bool same(int x, int y){ return find(x) == find(y); }