#include "bits/stdc++.h"
using namespace std;
#define fastcin {\
    cin.tie(0);\
    ios::sync_with_stdio(false);\
}
#define rep(i, a, b) for(int i = a; i < b; i++)
#define print(x) cout << x << "\n"
#define MOD 1000000007

int a[1000001];
int getA(int n) {
    a[1] = 1;
    a[2] = 2;
    a[3] = 2;
    rep(i, 4, n+1) {
        a[i] = (a[i-2] + a[i-3])%MOD;
    }
    return a[n];
}
int main() {
    fastcin;
    int n, ans;
    cin >> n;
    ans = getA(n);
    print(ans);
    return 0;
}