#include <bits/stdc++.h>
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<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int N,P;
const ll mo=1000000007;

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>>N>>P;
	cout<<(P-1)*modpow(P-2,N-1)%mo<<endl;
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}

#include<cstdio>
#include<algorithm>
#define mod 1000000007
using namespace std;
typedef long long ll;
#define gc() getchar()
inline bool ig(char c){return c>='0'&&c<='9';}
inline void read(ll &oi){char c;ll f=1,res=0;while(c=gc(),(!ig(c))&&c^'-');c^'-'?res=(c^48):f=-1;while(c=gc(),ig(c))res=res*10+(c^48);oi=f*res;}
inline void print(ll oi){if(oi<0)putchar('-'),oi=~oi+1;if(oi>9)print(oi/10);putchar(oi%10+48);}
ll n,m;
inline ll fastmul(ll a,ll b){
	ll res=1;
	while(b){
		if(b%2)res*=a,res%=mod;
		a*=a;a%=mod;b>>=1;
	}
	return res%mod;
}
int main(){
	read(n);read(m);print((m-1)*fastmul(m-2,n-1)%mod);putchar('\n');
	return 0;
}