陈向坤

#include<bits/stdc++.h>
using namespace std;
int n,a[10000005];
int main()
{
	cin>>n;
	a[1] = a[2] = 1;
	for(int i=3;i<=n;i++)
	{
		a[i] = a[i-1] + a[i-2];
        a[i]%=1000000007;
	}
    
	cout<<a[n];
	return 0;
}