#include<iostream>
#include<vector>
#include<string>
#include<algorithm>	
#include<map>
#include<set>
#include<utility>
#include<cmath>
#include<cstring>
#include<queue>
#include<cstdio>
#include<sstream>
#include<iomanip>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define pb push_back
#define mp make_pair
#define all(in) in.begin(),in.end()
#define shosu(x) fixed<<setprecision(x)
using namespace std;
//kaewasuretyuui
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pii> vp;
typedef vector<vp> vvp;
typedef pair<int,pii> pip;
typedef vector<pip>vip;
const double PI=acos(-1);
const double EPS=1e-8;
const int inf=1<<30;
int main(){
	ll n,m;
	cin>>n>>m;
	ll r=-1,l=1e18+10;
	while(l-r>1){
		ll h=(l+r)/2;
		ll t=h;
		bool H=false;
		rep(i,n-1){
			if(t<t/m+1)H=true;
			t-=t/m+1;
		}
		if(!H)l=h;
		else r=h;
	}
	cout<<l<<endl;
}