n=gets.to_i
if n==1
 puts 1
 exit
elsif n==2
 puts 1
 exit
elsif n==3
 puts 3
 exit
end
m=10**9+7
a=Hash.new(0)
b=Hash.new(0)
c=Hash.new(0)
a[1]=1
b[2]=1
c[3]=1
ans=0
loop{
 x=Hash.new(0)
 y=Hash.new(0)
 z=Hash.new(0)
 a.each{|k,v|
  if k+2 < n
    y[k+2]=(y[k+2]+v)%m
  elsif k+2==n
    ans=(ans+v)%m
  end
  if k+3 < n
    z[k+3]=(z[k+3]+v)%m
  elsif k+3==n
    ans=(ans+v)%m
  end
 }
 b.each{|k,v|
  if k+1 < n
    x[k+1]=(x[k+1]+v)%m
  elsif k+1==n
    ans=(ans+v)%m
  end
  if k+3 < n
    z[k+3]=(z[k+3]+v)%m
  elsif k+3==n
    ans=(ans+v)%m
  end
 }
 c.each{|k,v|
  if k+1 < n
    x[k+1]=(x[k+1]+v)%m
  elsif k+1==n
    ans=(ans+v)%m
  end
  if k+2 < n
    y[k+2]=(y[k+2]+v)%m
  elsif k+2==n
    ans=(ans+v)%m
  end
 }
 a,b,c=x,y,z
 break if a.empty? && b.empty? && c.empty?
}
puts ans