#include<bits/stdc++.h>
#define int long long
using namespace std;
int b[100005];
signed main()
{
	int n , sum = 0;
	int a[100005];
	cin >> n;
	if(n <= 0) cout << "0" << endl;
	int ans = n;
	for(int i = 1;i <= n;i++)
	{
		b[sum] = n & 1;
		if((sum & 1) && (ans[sum] & 1))
		{
			ans++;
		}
		sum++:
	}
	if(sum)
	{
		for(int i = sum - 1;i >= 1;i++)
		{
			cout << ans[i];
		}
	}
	cout << endl;
	return 0;
}