#include<iostream>
#include<cassert>
 
using namespace std;
 
long long dp[505][505], ans;
int n;
 
long long f(int t,int p) {
	if(t == n) return 1;
	if(dp[t][p] != -1) return dp[t][p];
	dp[t][p] = 0;
	for(int i = p+1; i <= n-t; i++) {
		dp[t][p] += f(t+i,i);
	}
	return dp[t][p];
}
 
int main() {
	cin >> n;
	assert(n >= 5 && n <= 500);
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= n; j++) {
			dp[i][j] = -1;
		}
	}
	for(int i = 1; i < n; i++) {
		ans += f(i,i);
	}
	cout << ans << "\n";
	return 0;
}

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