#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int bellNumber(int n)
{
   int bell[n+1][n+1];
   bell[0][0] = 1;
   for (int i=1; i<=n; i++)
   {
      bell[i][0] = bell[i-1][i-1];
      for (int j=1; j<=i; j++)
         bell[i][j] = bell[i-1][j-1] + bell[i][j-1];
   }
   return bell[n][0];
}

int main(){
    int n; 
    scanf("%d",&n);
    int *m = malloc(sizeof(int) * n);
    for(int m_i = 0; m_i < n; m_i++){
       scanf("%d",&m[m_i]);
    }
    printf("%d", bellNumber(8) % 1000000007);
    return 0;
}