#include <iostream>

using namespace std;
typedef long long ll;
ll mod = 1000000007;
ll pw(ll a,ll x){
    ll ret = 1; a %= mod;
    while(x){
        if(x&1) (ret *= a) %= mod;
        x /= 2; (a *= a) %= mod;
    }
    return ret;
}

int main(){
    ll n,k,inv = (mod + 1)/2; cin >> n >> k;
    ll ans = (pw((k + 3)%mod*k%mod*inv%mod,n) - pw((k + 1)%mod*k%mod*inv%mod,n) + mod)%mod;
    while(ans<0) ans += mod;
    cout << ans << endl;
}