#pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include<bits/stdc++.h> #define rep(i,n) for(ll i=0;i<(n);++i) #define reps(i,n) for(ll i=1;i<=(n);++i) #define repr(i,n) for(ll i=2;i*i<=(n);++i) #define ll long long #define all(x) (x).begin(),(x).end() #define sz(x) ((string)(x).size()) #define pb push_back #define pob pop_back() #define MMod (ll)1000000007 #define mmod (ll)998244353 #define setp(x) setprecision((ll)(x)) #define INF (ll)(1000000000000000000) #define mp make_pair using namespace std; using pii=pair<int, int>; using pll=pair<ll,ll>; using vi=vector<int>; using vc=vector<char>; using vb=vector<bool>; using vl=vector<long long>; using vvi=vector<vi>; using vvl=vector<vl>; using vvc=vector<vc>; using vvb=vector<vb>; using vpi=vector<pii>; using vpl=vector<pair<ll,ll>>; using vs=vector<string>; using pqi=priority_queue<int>; vpi fs={mp(1,0),mp(-1,0),mp(0,1),mp(0,-1)}; const ll inf=1e18; int main(){ ll h,a; cin>>h>>a; ll k=0; while(h>0){ k++; h/=a; } ll x=1; rep(i,k) x*=2; cout<<x-1<<endl; return 0; }