#include<bits/stdc++.h>
using namespace std;
int main()
{
	const int MOD = 1000000;
	int i, n;
	long long S = 0;
	scanf("%d", &n);
	for( i = n; i >= 1; i-- )
		S = (S + 1) * i % MOD;
	printf("%lld\n", S);
	return 0;
}