#include using namespace std; typedef long long int ll; typedef pair P; typedef vector VI; typedef vector VVI; const ll MOD = 1000000007; const ll INF = 1e18; #define REP(i, n) for(int i = 0; i < n; i++) #define ALL(v) v.begin(), v.end() ll power(ll x, ll y) { if (y==0) return 1; else if (y==1) return x%MOD; else if (y%2==0) { ll pow=power(x,y/2); return (pow*pow)%MOD; } else { ll pow=power(x,y/2); return ((pow*pow)%MOD)*x%MOD; } } ll divid(ll x, ll y) { return ((x%MOD)*power(y,MOD-2))%MOD; } int main(){ ll n, k; cin >> n >> k; ll ans=1; ll kk=k; kk%=MOD; kk*=(kk+1); kk%=MOD; kk=divid(kk,2); REP(i,n){ ans=(ans*kk)%MOD+(ans*k)%MOD; ans%=MOD; } ll m=1; REP(i,n){ m=(m*kk)%MOD; } ans-=m; ans+=MOD; ans%=MOD; cout << ans << endl; return 0; }