//什么时候我才能有杜爷一半强啊/kk
#include<cstdio>
const int N=55;
int n,p[N],pos[N],mx[N],mn[N];
long long f[N][N][N][N],s[N][N][N][N];
int Max(int a,int b){return a>b?a:b;}
int Min(int a,int b){return a<b?a:b;}
int read(){
	char ch=getchar();int nn=0,ssss=1;
	while(ch<'0'||ch>'9'){if(ch=='-')ssss*=-1;ch=getchar();}
	while(ch>='0'&&ch<='9'){nn=nn*10+(ch-'0');ch=getchar();}
	return nn*ssss;
}
bool solve(){
	for(int i=1;i<=n;i++){
		mx[i]=mn[i]=p[i]=read();
		pos[p[i]]=i;f[i][i][p[i]][p[i]]=1;
		for(int d=1;d<=p[i];d++)
			for(int u=p[i];u<=n;u++)
				s[i][i][d][u]=1;
	}
	//f[left][right][low][high]
	for(int len=2;len<=n;len++){
		for(int l=1;l+len-1<=n;l++){
			int r=l+len-1;
			mn[l]=Min(mn[l],p[r]);
			mx[l]=Max(mx[l],p[r]);
			if(l==1&&r==4)
				while(0);
			for(int u=mx[l];u>=mn[l];u--){
				if(pos[u]<l||pos[u]>r)continue;
				f[l][r][u][u]=1;
				for(int d=u-1;d>=mn[l];d--){
					if(pos[d]<l||pos[d]>r)continue;
					int np=pos[u];
					for(int k=d;k<u;k++){
						f[l][r][d][u]+=f[l][np-1][d][k];
						f[l][r][d][u]+=f[l][np-1][d][k]*s[np+1][r][k+1][u-1];
						f[l][r][d][u]+=f[np+1][r][d][k];
					}
					//printf("f[%d][%d][%d][%d]=%lld\n",l,r,d,u,f[l][r][d][u]);
				}
			}
			for(int nl=1;nl<=n;nl++)
				for(int d=1;d+nl-1<=n;d++){
					int u=d+nl-1;
					s[l][r][d][u]=f[l][r][d][u];
					s[l][r][d][u]+=s[l][r][d+1][u];
					s[l][r][d][u]+=s[l][r][d][u-1];
					s[l][r][d][u]-=s[l][r][d+1][u-1];
				}
		}
	}
	printf("%lld\n",s[1][n][1][n]);
	for(int i=1;i<=n;i++)
		for(int j=1;j<=n;j++)
			for(int d=1;d<=n;d++)
				for(int u=1;u<=n;u++)
					f[i][j][d][u]=s[i][j][d][u]=0;
	return 0;
}
int main(){
	//freopen("J.in","r",stdin);
	while(~scanf("%d",&n))solve();
}