#include<iostream>
#include<vector>
using ll = long long;


struct mint{
    static constexpr int  m = 1000000007;
    int x;
    mint() : x(0){}
    mint(ll x_):x(x_%m){if(x<0)x+=m;}
    int val(){return x;}
    mint &operator+=(mint b){if((x+=b.x)>=m)x-=m; return *this;}
    mint &operator-=(mint b){if((x-=b.x)<0)x+=m; return *this;}
    mint &operator*=(mint b){x=ll(x)*b.x%m; return *this;}
    mint pow(ll e) const {
        mint r = 1,b =*this;
        while(e){
            if(e&1) r*=b;
            b*=b;
            e>>=1;
        }
        return r;
    }
    mint inv(){return pow(m-2);}
    mint &operator/=(mint b){return *this*=b.pow(m-2);}
    friend mint operator+(mint a,mint b){return a+=b;}
    friend mint operator-(mint a,mint b){return a-=b;}
    friend mint operator/(mint a,mint b){return a/=b;}
    friend mint operator*(mint a,mint b){return a*=b;}
    friend bool operator==(mint a,mint b){return a.x==b.x;}
    friend bool operator!=(mint a,mint b){return a.x!=b.x;}
};


namespace po167{
template<class T>
struct Binomial{
    std::vector<T> fact_vec, fact_inv_vec;
    void extend(int m = -1){
        int n = fact_vec.size();
        if (m == -1) m = n * 2;
        if (n >= m) return;
        fact_vec.resize(m);
        fact_inv_vec.resize(m);
        for (int i = n; i < m; i++){
            fact_vec[i] = fact_vec[i - 1] * T(i);
        }
        fact_inv_vec[m - 1] = T(1) / fact_vec[m - 1];
        for (int i = m - 1; i > n; i--){
            fact_inv_vec[i - 1] = fact_inv_vec[i] * T(i);
        }
    }
    Binomial(int MAX = 2){
        fact_vec.resize(1, T(1));
        fact_inv_vec.resize(1, T(1));
        extend(MAX + 1);
    }

    T fact(int i){
        if (i < 0) return 0;
        while (int(fact_vec.size()) <= i) extend();
        return fact_vec[i];
    }
    T invfact(int i){
        if (i < 0) return 0;
        while (int(fact_inv_vec.size()) <= i) extend();
        return fact_inv_vec[i];
    }
    T C(int a, int b){
        if (a < b || b < 0) return 0;
        return fact(a) * invfact(b) * invfact(a -b);
    }
    T P(int a, int b){
        if (a < b || b < 0) return 0;
        return fact(a) * invfact(a - b);
    }
    T inv(int a){
        if (a < 0) return inv(-a) * T(-1);
        if (a == 0) return 1;
        return fact(a - 1) * invfact(a);
    }
};
}



int main(){
    int h,w;
    std::cin >> h >> w;
    po167::Binomial<mint> table(h + w);
    mint ans = 0;
    for(int i = 0; i <= h; i++){
        ans += mint(-1).pow(i) * table.C(h, i) * (mint(2).pow(h - i) - 1).pow(w);
    }
    std::cout << ans.val() << "\n";
}