#include #include #include #include #include #include #include using namespace std; const int surplus = 1000000007; int n; int dp[1000001][2]; int main(){ cin >> n; dp[1][0] = 1; for (int i = 2; i <= n; i++){ dp[i][0] = dp[i - 1][0] + dp[i - 1][1] - dp[i - 2][0]; dp[i][1] = dp[i - 1][0]; dp[i][0] %= surplus; dp[i][1] %= surplus; } cout << (dp[n][0] + dp[n][1])%surplus << endl; return 0; }