#include<cstdio>
#include<atcoder/modint>
using namespace atcoder;
using Mint = modint1000000007;
constexpr int MAX = 1000000;
using ll = long long;
int main(){
    int H, W;
    scanf("%d %d", &H, &W);
    Mint fact[MAX+1];
    fact[0] = Mint::raw(1);
    for (int i = 1; i <= MAX; i++) fact[i] = fact[i-1]*Mint::raw(i);
    Mint ifact[MAX+1];
    ifact[MAX] = fact[MAX].inv();
    for (int i = MAX; (i); i--) ifact[i-1] = ifact[i]*Mint::raw(i);
    Mint answer = ifact[H]*((Mint::raw(1) - ifact[2].pow(H)).pow(W) - Mint::raw(1));
    for (int i = 1; i < H; i++)
    {
        if(i&1) answer -= ifact[i]*ifact[H-i]*ifact[2].pow((ll)W*i)*(Mint::raw(1) - ifact[2].pow(H-i)).pow(W);
        else answer += ifact[i]*ifact[H-i]*ifact[2].pow((ll)W*i)*(Mint::raw(1) - ifact[2].pow(H-i)).pow(W);
    }
    printf("%u\n", ((answer*fact[H] + Mint::raw(1))*Mint::raw(2).pow((long long)H*W)).val());
}