#include #include #include #include #include #include #include #include #include #include #include #include #include #define REP(i, n) for(int i = 0;i < (n); i++) #define REP2(i, x, n) for(int i = (x); i < (n); i++) #define REPR(i, n) for(int i = (n); i >= 0; i--) #define ALL(a) (a).begin(),(a).end() #define SORT(c) sort((c).begin(),(c).end()) #define DESCSORT(c) sort(c.begin(), c.end(), greater()) #define LL long long int #define LD long double #define PI 3.14159265358979 using namespace std; //================================================ int main() { ios::sync_with_stdio(false); cin.tie(0); int N; cin >> N; int *dp = new int[1000001]{}; dp[1] = 1; dp[2] = 2; dp[3] = 2; REP2(i, 4, N + 1) dp[i] = (dp[i - 2] + dp[i - 3]) % 1000000007; cout << dp[N] << "\n"; return 0; }