#include <iostream> using namespace std; const int MOD = 1e9 + 7; int main() { int n; cin >> n; long long a = 1, b = 3; // dp[0], dp[2] for (int i = 4; i <= n; i += 2) { long long c = (4 * b - a + MOD) % MOD; a = b; b = c; } cout << b << endl; return 0; }