MOD = 10**9+7

def create_fact_mod(num_max)
    $fmod = Array.new(num_max + 1)
    $fmod[0] = 1
    $fmod[1] = 1
    (2..num_max).each do |i|
        $fmod[i] = ($fmod[i - 1] * i) % MOD
    end
end

def create_seq_inv_mod(num_max)
    $simod = Array.new(num_max + 1)
    $simod[0] = 1
    $simod[1] = 1
    (2..num_max).each do |i|
        $simod[i] = (MOD - MOD / i) * $simod[MOD % i] % MOD
    end
end

def create_fact_inv_mod(num_max)
    $fimod = Array.new(num_max + 1)
    $fimod[0] = 1
    $fimod[1] = 1
    (2..num_max).each do |i|
        $fimod[i] = ($fimod[i - 1] * $simod[i]) % MOD
    end
end

def create_mod_tables(n)
    create_fact_mod(n)
    create_seq_inv_mod(n)
    create_fact_inv_mod(n)
end

def comb_mod(n, k)
    return $fmod[n] * $fimod[n - k] * $fimod[k] % MOD
end

def perm_mod(n, k)
    return $fmod[n] * $fimod[n - k] % MOD
end


N = gets.to_i
as = gets.split.map(&:to_i)

create_mod_tables(N)

ans = 0
N.times do |i|
    ans += as[i] * comb_mod(N-1, i)
    ans %= MOD
end

puts ans