//
// Compute the average probability between two agents, each with a domain size of m
// who find each other acceptable and can rank each other in m ways (therefore m*m) possibilities
//
import java.util.*;

public class PStable { 

    static int n;
    static double p;

    static double pStable(int m){
	double p = 0.0;
	for (int pref_i=0;pref_i<m;pref_i++)
	    for (int pref_j=0;pref_j<m;pref_j++){
		int Xi = pref_i; // number of agents preferred by agent i to agent j;
		int Yi = m-pref_i; // number of agents not preferred by agent j
		int Xj = pref_j;
		int Yj = m-pref_j;
		int num = Xi*Xj + Xi*Yj + Xj*Yi + 1;
		int denom = (m+1)*(m+1);
		p = p + ((double)num)/((double)denom);
		//System.out.print("("+ pref_i +","+ pref_j +") ");
		//System.out.format("%.6f ",((double)num)/((double)denom));
		//System.out.println();
	    }
	//System.out.format("P mean: %.5f ", p/(m*m));
	//System.out.println();
	return p/(m*m);
    }
  
    public static void main(String[] args) throws Exception {
	n = Integer.parseInt(args[0]);
	double p = 0.0;
	for (int i=0;i<100;i++){
	    p = p + 0.01;
	    int m = (int)(p*(n-1)+1);
	    double pStable = pStable(m);
	    double logPStable = Math.log(pStable);
	    double pSol = Math.pow(pStable,(double)(n*(n-1)/2)*p);
	    double logPSol = p*(double)(n*(n-1)/2)*logPStable;
	    double states = n*Math.log(m);
	    double kappa = (-logPSol)/states;
	    if (m>1){
	    System.out.format("p %.3f m %d  pStable %.5f logPstable: %.5f logPSol %.10f logStates: %.2f kappa: %.5f",
			      p,m,pStable,logPStable,logPSol,states,kappa);
	    System.out.println();
	    }
	}
    }
}