import java.util.Scanner;

public class DiseaseSpread {
	
  public static int runSimulation(int popSize, int rate) {
	  int numberInfected = 1;
	  int currentDay = 0;
	  while (numberInfected < popSize/2) {
		  numberInfected += numberInfected*rate;
		  currentDay++;
	  }
	  return currentDay;
  }
  
  public static void main(String[] args) {
	  Scanner input = new Scanner(System.in);
	  
	  System.out.print("Population size? ");
	  int populationSize = input.nextInt();
	  
	  System.out.print("Infection rate? ");;
	  int infectionRate = input.nextInt();
	  
	  input.close();
	  
	  int numDays = runSimulation(populationSize, infectionRate);
	  System.out.println("Half the population is infected by " + numDays);
  }
}