#include using namespace std; typedef signed long long ll; #define _P(...) (void)printf(__VA_ARGS__) #define FOR(x,to) for(x=0;x<(to);x++) #define FORR(x,arr) for(auto& x:arr) #define FORR2(x,y,arr) for(auto& [x,y]:arr) #define ALL(a) (a.begin()),(a.end()) #define ZERO(a) memset(a,0,sizeof(a)) #define MINUS(a) memset(a,0xff,sizeof(a)) template bool chmax(T &a, const T &b) { if(a bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;} //------------------------------------------------------- int H,W; const ll mo=1000000007; ll comb(ll N_, ll C_) { const int NUM_=2400001; static ll fact[NUM_+1],factr[NUM_+1],inv[NUM_+1]; if (fact[0]==0) { inv[1]=fact[0]=factr[0]=1; for (int i=2;i<=NUM_;++i) inv[i] = inv[mo % i] * (mo - mo / i) % mo; for (int i=1;i<=NUM_;++i) fact[i]=fact[i-1]*i%mo, factr[i]=factr[i-1]*inv[i]%mo; } if(C_<0 || C_>N_) return 0; return factr[C_]*fact[N_]%mo*factr[N_-C_]%mo; } ll modpow(ll a, ll n = mo-2) { ll r=1;a%=mo; while(n) r=r*((n%2)?a:1)%mo,a=a*a%mo,n>>=1; return r; } void solve() { int i,j,k,l,r,x,y; string s; cin>>H>>W; ll ret=0; FOR(i,H+1) { ll a=comb(H,i); ll b=modpow(modpow(2,H-i)-1,W); if(i%2==0) { ret+=a*b%mo; } else { ret-=a*b%mo; } } cout<<(ret%mo+mo)%mo<