import java.util.Scanner;

public class code205 {
	

	/**
	 * 成绩统计
	 */
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		System.out.print("STB的成绩是:");
		int stb = input.nextInt();  //STB分数
		System.out.print("Java的成绩是:");
		int java = input.nextInt();  //Java分数
		System.out.print("SQL的成绩是:");
		int sql = input.nextInt();  //SQL分数
		int diffen;    //分数差
		double avg;    //平均分
		System.out.println("----------------------------------");
		System.out.println("STB\tJava\tSQL");
		System.out.println(stb+"\t"+java+"\t"+sql);
		System.out.println("-----------------------------------");
		diffen = java - sql;                 //计算机Java课和SQL课的成绩差
		System.out.println("Java和SQL的成绩差:"+ diffen);
		avg = (stb + java + sql) / 3;       //计算平均分
	    System.out.println("3门课的平均分是：" + avg);
	}

}