///////    MaxGurad.java    ///////

class MaxGuard
{    public MaxGuard(int e)
     {   maxValue = e; }
     
     public synchronized int getMax()
     {    return maxValue;   }

     public synchronized void setMax(int e)
     {    maxValue = Math.max(maxValue, e);   }

     private int maxValue;
}

class FindMax extends Thread
{ public FindMax(int[] ar, int l, 
		 int h, MaxGuard m)
  {   arr = ar;  low = l+1; high = h;
      l_max = arr[l];  xobj = m;
  }
  public void run()
  { try
    {  while ( low < high )
       {   int n = Math.min(incr, high-low);
           for (int i=low; i <= low+n; i++)
               l_max = Math.max(l_max, arr[i]); // (1)
           sleep(5);
           low += n;
       }
    }  catch(InterruptedException e)
       {   return ;  }
    xobj.setMax(l_max);                         // (2)
  }

  private int l_max;      // local maximum
  private int low, high;  // array range
  private int incr = 10;  // increment
  private int[] arr;      // array ref
  private MaxGuard xobj;  // mutex object
}

class MaxTest
{ public static void main(String[] args)
         throws InterruptedException
  {  int[] a = new int[1024];
     for (int i=0; i < 1024; i++)                   // (A)
         a[i] = (int) (100000*Math.random());
     int nt=0;
     if ( args.length == 1 )   
         nt = Integer.valueOf(args[0]).intValue();
     if ( nt <= 0 ) nt = 4;                         // (B)
     MaxGuard ans = new MaxGuard(a[0]);
     FindMax[] slave = new FindMax[nt];
     int range = 1024/nt;                           // (C)
     int high, low = 0;
     for (int i=0; i < nt-1; i++)
     {   high = low + range -1;
         slave[i] = new FindMax(a, low, high, ans); // (D)
         low = high + 1;
     }
     slave[nt-1] = new FindMax(a, low, 1023, ans);
     for (int i=0; i < nt; i++)
         slave[i].start();                          // (E)
     for (int i=0; i < nt; i++)
         slave[i].join();
     System.out.println("Maximum = " + ans.getMax());
  }
}