In.java

import java.util.*;

/**
 * This class provides static methods for easily reading
 * input from STDIN:
 *
 * nextLine reads a string
 * nextInt reads an integer
 * nextDouble reads a double
 * nextChar reads a character
 *
 * All methods consume the end-of-line character.
 */
public class In {
	/**
	 * A singleton instance of Scanner used for reading all input
	 * from STDIN.
	 */
	private static final Scanner scanner = new Scanner(System.in);

	/**
	 * The constructor is private because no instances of this
	 * class should be created. All methods are static and can
	 * be directly invoked on the class itself.
	 */
	private In() {}

	/**
	 * Read the next line of text.
	 *
	 * @return the line as a String
	 */
	public static String nextLine() {
		return scanner.nextLine();
	}

	/**
	 * Read the next line as an integer.
	 *
	 * @return the integer that was read
	 */
	public static int nextInt() {
		int value = scanner.nextInt();
		scanner.nextLine(); // read the "\n" as well
		return value;
	}

	/**
	 * Read the next line as a double.
	 *
	 * @return the double that was read
	 */
	public static double nextDouble() {
		double value = scanner.nextDouble();
		scanner.nextLine();
		return value;
	}

	/**
	 * Read the first character of the next line of text.
	 *
	 * @return the character that was read
	 */
	public static char nextChar() {
		return scanner.nextLine().charAt(0);
	}
}