MOD = 10 ** 9 + 7
INF = 10 ** 10
import sys
sys.setrecursionlimit(100000000)
dy = (-1,0,1,0)
dx = (0,1,0,-1)

def main():
    n,p = map(int,input().split())
    if n == 1:
        print(0)
        return
    dp = [0] * n
    dp[1] = 1
    cum = [0] * n
    cum[1] = 1

    for i in range(2,n):
        dp[i] = (p * dp[i - 1] + dp[i - 2])%MOD
        cum[i] = (cum[i - 1] + dp[i])%MOD
    
    ans = 0
    for i in range(n):
        ans += dp[i] * cum[i]
        ans %= MOD
    
    print(ans)

if __name__ =='__main__':
    main()