/*
 * Solution for Homework 1
 * by Sriram Pemmaraju, 9/11
 * I started from Ezra Sidran's solution to Quiz 1
 */


import java.io.*;
import java.util.*;
// Note: you do not need to import java.util.Random because java.util.* includes this

class TwoRolls{

	private static BufferedReader stdin = new BufferedReader( new InputStreamReader( System.in ) );

	// main method
	public static void main (String args[]) {

		// Prompt the user
		System.out.println( "Type in the size of the dice. " );

		try{
			// Read a line of text from the user.
        		String input = stdin.readLine();

			// converts a String into an int value
			int number = Integer.parseInt( input );

			Random myRandom = new Random();

			// Declare an array and allocate the right amount of memory to
			// it; for two n-sided dice, the number of possible sums is
			// 2*n-1. Initialize the array to all zeroes.
			int[] ndigits = new int[2*number-1];
			for (int i = 0; i < number; i++)
				ndigits[i] = 0;

			// Test the random number generator a whole lot
			for (long i=0; i < 100000; i++) {
				// generate a new random number between 0 and number-1
				// adding one gives us a random number between 1 and number
				int x = 1 + myRandom.nextInt(number);
				int y = 1 + myRandom.nextInt(number);

		      		// The fact that the sum is x + y is stored in slot
				// with index x + y - 2.
		      		ndigits[x+y-2]++;
		  	}// end for i

		  	for (int i = 0; i < 2*number-1; i++)
		  		System.out.println((i+2)+": " + ndigits[i]);

		} // End try
		catch(java.io.IOException e)
               	{
               		System.out.println(e);
               	}
	} // end of Main
} // end of RandomTest class