Problem: Ilya got tired of sports programming, left university and got a job in the subway. He was given the task to determine the escalator load factor. 

Let's assume that n people stand in the queue for the escalator. At each second one of the two following possibilities takes place: either the first person in the queue enters the escalator with probability p, or the first person in the queue doesn't move with probability (1 - p), paralyzed by his fear of escalators and making the whole queue wait behind him.

Formally speaking, the i-th person in the queue cannot enter the escalator until people with indices from 1 to i - 1 inclusive enter it. In one second only one person can enter the escalator. The escalator is infinite, so if a person enters it, he never leaves it, that is he will be standing on the escalator at any following second. Ilya needs to count the expected value of the number of people standing on the escalator after t seconds. 

Your task is to help him solve this complicated task.

Input

The first line of the input contains three numbers n, p, t (1 ≤ n, t ≤ 2000, 0 ≤ p ≤ 1). Numbers n and t are integers, number p is real, given with exactly two digits after the decimal point.

Output

Print a single real number — the expected number of people who will be standing on the escalator after t seconds. The absolute or relative error mustn't exceed 10 - 6.

Examples

Input

1 0.50 1


Output

0.5


Input

1 0.50 4


Output

0.9375


Input

4 0.20 2


Output

0.4

Solution (in JAVA):

Solution:
//pakage joney_000[let_me_start]
 
import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*;
 /******************** Main Class ***********************/

public class D
{   
    public static InputStream inputStream = System.in;
    public static OutputStream outputStream = System.out;
    public static FastReader in = new FastReader(inputStream);;
    public static PrintWriter out = new PrintWriter(outputStream);;
    /*
    Overhead [Additional Temporary Strorage]
    */
    public static int tempints[] = new int[100005];
    public static long templongs[] = new long[100005];
    public static double tempdoubles[] = new double[100005];
    public static char tempchars[] = new char[100005];
    public static long mod = 1000000000+7;
    
        public static void main(String[] args) throws java.lang.Exception{
        //let_me_start 
         
        int n = i(); double p = d();int t= i();
         //int arr[] = is((int)n);
         //String ans = "NO";
         double ans=0;
         double[][] dp  = new double[t+2][n+2];
         dp[0][0]=1;
         for(int i=0;i<=t;i++){
              for(int j=0;j<=n;j++){
                if(j==n){dp[i+1][j] += dp[i][j];continue;}
                dp[i+1][j+1] += p*dp[i][j];
                dp[i+1][j] += (1-p)*dp[i][j];
              }
         }
        for(int i=0;i<=n;i++)ans+= i*dp[t][i];
        out.write(""+ans+"\n");
        out.flush();
        return;
        }    


//****************************** Utilities ***********************//

 public static boolean isPrime(long n)throws Exception{
  if(n==1)return false;
  if(n<=3)return true;
  if(n%2==0)return false;
  for(int i=2 ;i <= Math.sqrt(n); i++){
   if(n%i==0)return false;
  }
  return true;
 }
 // sieve
 public static int[] primes(int n)throws Exception{       // for(int i=1;i<=arr.length-1;i++)out.write(""+arr[i]+" ");
  boolean arr[] = new boolean[n+1];
  Arrays.fill(arr,true);
  for(int i=1;i<=Math.sqrt(n);i++){
    if(!arr[i])continue;
    for(int j = 2*i ;j<=n;j+=i){
        arr[i]=false;
    }
  }
  LinkedList<Integer> ll = new LinkedList<Integer>();
  for(int i=1;i<=n;i++){
   if(arr[i])ll.add(i);
  }
  n = ll.size();
  
  int primes[] = new int[n+1];
  for(int i=1;i<=n;i++){
    primes[i]=ll.removeFirst();
  }
  return primes;
 }
 public static long gcd (long a , long b)throws Exception{
  if(b==0)return a;
  return gcd(b , a%b);
 }
 public static long lcm (long a , long b)throws Exception{
  if(a==0||b==0)return 0;
  return (a*b)/gcd(a,b);
 }
 public static long mulmod(long a , long b ,long mod)throws Exception{
   if(a==0||b==0)return 0;
   if(b==1)return a;
   long ans = mulmod(a,b/2,mod);
   ans = (ans*2)% mod;
   if(b%2==1)ans = (a + ans)% mod;
   return ans;
 }
 public static long pow(long a , long b ,long mod)throws Exception{
   if(b==0)return 1;
   if(b==1)return a;
   long ans = pow(a,b/2,mod);
   ans = (ans * ans)% mod;
   if(b%2==1)ans = (a * ans)% mod;
   return ans;
 }
 // 20*20   nCr Pascal Table
 public static long[][] ncrTable()throws Exception{
  long ncr[][] = new long[21][21];
  for(int i=0 ;i<=20 ;i++){ncr[i][0]=1;ncr[i][i]=1;}
  for(int j=0;j<=20 ;j++){
   for(int i=j+1;i<= 20 ;i++){
    ncr[i][j] = ncr[i-1][j]+ncr[i-1][j-1];
   }
  }
  return ncr;
 }
//*******************************I/O******************************//    
public static int i()throws Exception{
 //return Integer.parseInt(br.readLine().trim());
 return in.nextInt();
}
public static int[] is(int n)throws Exception{
  //int arr[] = new int[n+1];
  for(int i=1 ; i <= n ;i++)tempints[i] = in.nextInt();  
 return tempints;
}
public static long l()throws Exception{
 return in.nextLong();
}
public static long[] ls(int n)throws Exception{
  for(int i=1 ; i <= n ;i++)templongs[i] = in.nextLong();  
 return templongs;
}

public static double d()throws Exception{
 return in.nextDouble();
}
public static double[] ds(int n)throws Exception{
  for(int i=1 ; i <= n ;i++)tempdoubles[i] = in.nextDouble();  
 return tempdoubles;
}
public static char c()throws Exception{
 return in.nextCharacter();
}
public static char[] cs(int n)throws Exception{
  for(int i=1 ; i <= n ;i++)tempchars[i] = in.nextCharacter();  
 return tempchars;
}
public static String s()throws Exception{
 return in.nextLine();
}
public static BigInteger bi()throws Exception{
 return in.nextBigInteger();
}
//***********************I/O ENDS ***********************//
//*********************** 0.3%f [precision]***********************//
/* roundoff upto 2 digits 
   double roundOff = Math.round(a * 100.0) / 100.0;
                    or
   System.out.printf("%.2f", val);
                    
*/
/*
  print upto 2 digits after decimal
  val = ((long)(val * 100.0))/100.0;
  
*/
}

class FastReader{

    private boolean finished = false;

    private InputStream stream;
    private byte[] buf = new byte[1024];
    private int curChar;
    private int numChars;
    private SpaceCharFilter filter;

    public FastReader(InputStream stream){
        this.stream = stream;
    }

    public int read(){
        if (numChars == -1){
            throw new InputMismatchException ();
        }
        if (curChar >= numChars){
            curChar = 0;
            try{
                numChars = stream.read (buf);
            } catch (IOException e){
                throw new InputMismatchException ();
            }
            if (numChars <= 0){
                return -1;
            }
        }
        return buf[curChar++];
    }

    public int peek(){
        if (numChars == -1){
            return -1;
        }
        if (curChar >= numChars){
            curChar = 0;
            try{
                numChars = stream.read (buf);
            } catch (IOException e){
                return -1;
            }
            if (numChars <= 0){
                return -1;
            }
        }
        return buf[curChar];
    }

    public int nextInt(){
        int c = read ();
        while (isSpaceChar (c))
            c = read ();
        int sgn = 1;
        if (c == '-'){
            sgn = -1;
            c = read ();
        }
        int res = 0;
        do{
            if(c==','){
                c = read();
            }
            if (c < '0' || c > '9'){
                throw new InputMismatchException ();
            }
            res *= 10;
            res += c - '0';
            c = read ();
        } while (!isSpaceChar (c));
        return res * sgn;
    }

    public long nextLong(){
        int c = read ();
        while (isSpaceChar (c))
            c = read ();
        int sgn = 1;
        if (c == '-'){
            sgn = -1;
            c = read ();
        }
        long res = 0;
        do{
            if (c < '0' || c > '9'){
                throw new InputMismatchException ();
            }
            res *= 10;
            res += c - '0';
            c = read ();
        } while (!isSpaceChar (c));
        return res * sgn;
    }

    public String nextString(){
        int c = read ();
        while (isSpaceChar (c))
            c = read ();
        StringBuilder res = new StringBuilder ();
        do{
            res.appendCodePoint (c);
            c = read ();
        } while (!isSpaceChar (c));
        return res.toString ();
    }

    public boolean isSpaceChar(int c){
        if (filter != null){
            return filter.isSpaceChar (c);
        }
        return isWhitespace (c);
    }

    public static boolean isWhitespace(int c){
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }

    private String readLine0(){
        StringBuilder buf = new StringBuilder ();
        int c = read ();
        while (c != '\n' && c != -1){
            if (c != '\r'){
                buf.appendCodePoint (c);
            }
            c = read ();
        }
        return buf.toString ();
    }

    public String nextLine(){
        String s = readLine0 ();
        while (s.trim ().length () == 0)
            s = readLine0 ();
        return s;
    }

    public String nextLine(boolean ignoreEmptyLines){
        if (ignoreEmptyLines){
            return nextLine ();
        }else{
            return readLine0 ();
        }
    }

    public BigInteger nextBigInteger(){
        try{
            return new BigInteger (nextString ());
        } catch (NumberFormatException e){
            throw new InputMismatchException ();
        }
    }

    public char nextCharacter(){
        int c = read ();
        while (isSpaceChar (c))
            c = read ();
        return (char) c;
    }

    public double nextDouble(){
        int c = read ();
        while (isSpaceChar (c))
            c = read ();
        int sgn = 1;
        if (c == '-'){
            sgn = -1;
            c = read ();
        }
        double res = 0;
        while (!isSpaceChar (c) && c != '.'){
            if (c == 'e' || c == 'E'){
                return res * Math.pow (10, nextInt ());
            }
            if (c < '0' || c > '9'){
                throw new InputMismatchException ();
            }
            res *= 10;
            res += c - '0';
            c = read ();
        }
        if (c == '.'){
            c = read ();
            double m = 1;
            while (!isSpaceChar (c)){
                if (c == 'e' || c == 'E'){
                    return res * Math.pow (10, nextInt ());
                }
                if (c < '0' || c > '9'){
                    throw new InputMismatchException ();
                }
                m /= 10;
                res += (c - '0') * m;
                c = read ();
            }
        }
        return res * sgn;
    }

    public boolean isExhausted(){
        int value;
        while (isSpaceChar (value = peek ()) && value != -1)
            read ();
        return value == -1;
    }

    public String next(){
        return nextString ();
    }

    public SpaceCharFilter getFilter(){
        return filter;
    }

    public void setFilter(SpaceCharFilter filter){
        this.filter = filter;
    }

    public interface SpaceCharFilter{
        public boolean isSpaceChar(int ch);
    }
}
 /******************** Pair class ***********************/
 
 class Pair implements Comparable<Pair>{
 public int a;
 public int b;
 public Pair(){
  this.a = 0;
  this.b = 0;
 }
 public Pair(int a,int b){
  this.a = a;
  this.b = b;
 }
 public int compareTo(Pair p){
  if(this.a==p.a){
   return this.b-p.b;  
  }
  return this.a-p.a; 
 }
 public String toString(){
  return "a="+this.a+" b="+this.b;
 }
 
}