#include<bits/stdc++.h>
using namespace std;
#define ll long long
int n;
ll mod,ans,fac[505],inv[505],ifac[505],f[505][505],g[505][505];
void init()
{
	fac[0]=inv[0]=inv[1]=ifac[0]=1;
	for(int i=1;i<=n;i++)fac[i]=fac[i-1]*i%mod;
	for(int i=2;i<=n;i++)inv[i]=(mod-mod/i*inv[mod%i]%mod)%mod;
	for(int i=1;i<=n;i++)ifac[i]=ifac[i-1]*inv[i]%mod;
}
ll C(int n,int m){return n<m||n<0||m<0?0:fac[n]*ifac[m]%mod*ifac[n-m]%mod;}
int main()
{
	freopen("toyy.in","r",stdin);
	freopen("toyy.out","w",stdout);
	scanf("%d%lld",&n,&mod);
	init();
	g[1][0]=1;
	for(int i=0;i<=n;i++)f[1][i]=1;
	for(int d=1;d<=n;d++)
	{
		for(int i=2;i<=n;i++)
		{
			long long sum=0;
			for(int j=1;j<i;j++)(sum+=f[i-j][d]*f[j][d-1]%mod*C(i-2,j-1)%mod)%=mod;
			f[i][d]=sum;
		}
		for(int i=1;i<=n;i++)g[i][d]=(f[i][d]-f[i][d-1]+mod)%mod;
	}
	for(int i=1;i<=n;i++)(ans+=g[n][i]*i%mod)%=mod;
	ans=1ll*ans*ifac[n-1]%mod;
	printf("%d\n",ans);
	return 0;
}