#include <cstdio>
#include <algorithm>
using namespace std;
const int N = 500 + 10;
int n;
unsigned long long f[N][N];
int main() {
    freopen("runa.in", "r", stdin);
    freopen("runa.out", "w", stdout);
    scanf("%d", &n);
    fill(f[0], f[0]+N, 1);
    for(int i=1; i<=n; i++)
        for(int j=1; j<=n; j++) {
            f[i][j] = f[i][j-1];
            if(i >= j) f[i][j] += f[i-j][j-1];
        }
    printf("%lld\n", f[n][n] - 1);
    return 0;
}