n, k = io.read("*n", "*n")
a = {}
asum = 0
for i = 1, n do
  a[i] = io.read("*n")
  asum = asum + a[i]
end
c = 0
for i = 1, n do
  c = c * k
  c = (c + a[i]) % asum
end
print(c)