MOD = 10 ** 9 + 7

n, p = map(int, input().split())

if n == 1:
  print(0)
  exit()

a = [0 for _ in range(n + 1)]
s = [0 for _ in range(n + 1)]
a[2] = 1
s[2] = 1
for i in range(3, n + 1):
  a[i] = (p * a[i - 1] + a[i - 2]) % MOD
  s[i] = (s[i - 1] + a[i]) % MOD

ans = 0
for i in range(1, n + 1):
  ans = (ans + a[i] * (s[n] - s[i - 1])) % MOD

print(ans)