# coding: utf-8
# Your code here!
import sys
readline = sys.stdin.readline
read = sys.stdin.read


n,p = map(int,read().split())
MOD = 1000000007

f = 0
s = 0
a = 0
b = 1

for i in range(n-1):
    #print(f,s,a,b)
    a,b = b,(a+p*b)%MOD
    s = (s+a)%MOD
    f = (f+a*s)%MOD    

#print(f,s,a,b)
print(f)