#include<bits/stdc++.h>
using namespace std;

using ll = long long;
//9223372036854775807
ll MOD = 1000000007;

int main() {
	ll n;
	cin >> n;
	ll f1=0,f2=1,f3;
	for(ll i = 0; i < n; i++) {
		f1%=MOD;
		f2%=MOD;
		f3=f1+f2;
		f3%=MOD;
		f1=f2;
		f2=f3;
	}
	cout << f1;
	return 0;
}