#include <bits/stdc++.h>

using namespace std;

#define REP(i,a,b) for(int i=a;i<(int)b;i++)
#define rep(i,n) REP(i,0,n)

int main() {
  int W,D;cin>>W>>D;
  rep(_, D-1) {
    W -= W/(D-_)/(D-_);
  }cout<<W<<endl;
  return 0;
}