#include <iostream>
using namespace std;
const int MOD = 1000000007;

int main() {
    int n;
    cin >> n;
    if(n == 0){
        cout << 0 % MOD;
        return 0;   
    }
    if((n == 1)||(n == 2)){
        cout << 1 % MOD;
        return 0;
    }
    long long a = 1;
    long long b = 1;
    long long res = 0;
    for(int i = 3; i <= n; i++){
        res = (a+b) % MOD;  // 防止溢出
        a = b;              
        b = res;
    }
    cout << res << endl;
    return 0;
}