/*
 *
 *
  Info-Arena 2.0 - preONI 2007 - Runda 2 - Culori
 *
 *
 */

#include<stdio.h>

#define INPUT "culori.in"
#define OUTPUT "culori.out"

FILE *fin=fopen(INPUT, "r"),*fout=fopen(OUTPUT, "w");

int n,a[300];

void citire();
void rezolvare();

int main()
{
  citire();
  if(n==1)
    fprintf(fout, "1\n");
  else
    rezolvare();
  fclose(fin);
  fclose(fout);
  return 0;
}

void citire()
{
  fscanf(fin, "%d", &n);
  for(int i=1;i<=2*n-1;++i)
    fscanf(fin, "%d", &a[i]);
}

void rezolvare()
{
  int drum=1;
  for(int i=3;i<=n;++i)
    if(a[i]==a[i-2])
    {
      drum*=2;
      drum%=9901;
    }
  int l=1;
  for(int i=2*n-1;i>=n+1&&l;--i)
    if(a[i]!=a[2*n-i])
    {
      l=0;
      fprintf(fout, "0\n");
    }
  if(l)
    fprintf(fout, "%d\n", drum);
}