import copy



P,K=map(int,input().split())
now=[0,0]
pnow=[1,0]

d=1000000007

for i in range(K):
  now=[0,0]
  now[0]+=pnow[0]*(P+1)
  now[0]+=pnow[1]*2
  now[1]+=pnow[0]*(P-1)
  now[1]+=pnow[1]*(P-2)*2
  now[0]%=d
  now[1]%=d
  pnow=copy.deepcopy(now)
print(now[0])