h,w = map(int,input().split())
mod = 10**9+7
fact = [1,1]
finv = [1,1]
inv = [0,1]
 
for i in range(2,h+5):
    fact.append((fact[-1]*i)%mod)
    inv.append((inv[mod%i]*(mod-mod//i))%mod)
    finv.append((finv[-1]*inv[-1])%mod)
 
def nCr(n,r,mod):
    if r > n:
        return 0
    else: 
        return fact[n]*finv[r]%mod*finv[n-r]%mod

ans = 0
flag = 1
for i in range(h):
    l = h-i
    w2 = pow(2,l,mod)-1
    p = pow(w2,w,mod)
    ans += flag * nCr(h,i,mod) * p %mod
    ans %= mod
    flag *= -1

print(ans)