$mod = 10**9+7

def pow(a,b)
  if b == 1
    a
  elsif b%2 == 0
    (pow(a,b/2)**2)%$mod
  else
    (a*pow(a,b/2)**2)%$mod
  end
end

def create_fact(n)
  for i in 2..n
    $fact[i] = ($fact[i-1]*i)%$mod
  end
end

def create_fact_inv(n)
  $fact_inv[n] = pow($fact[n],$mod-2)
  n.downto(1) do |i|
    $fact_inv[i-1] = ($fact_inv[i]*i)%$mod
  end
end

def create_inv(n)
  for i in 1..n
    $inv[i] = ($fact[i-1]*$fact_inv[i])%$mod
  end
end

def create_table(n)
  $fact = Array.new(n+1,1)
  $fact_inv = Array.new(n+1,1)
  $inv = Array.new(n+1,0)
  create_fact(n)
  create_fact_inv(n)
  create_inv(n)
end

def combi(a,b)
  (($fact[a]*$fact_inv[b])%$mod)*$fact_inv[a-b]%$mod
end

n = gets.to_i
a = gets.split.map(&:to_i)
create_table(n)
ans = 0
n.times do |i|
    ans += a[i]*combi(n-1,i)
    ans %= $mod
end
puts ans