Java：在同一个类中,分别定义求两个整数的方法 和 三个小数之和的方法。 并执行代码，求出结果

import java.util.Scanner;
public class TestDemo6 {
 public static int sum(int n, int m) {
  int sum = m + n;  
  return sum;
 }
 public static double sum(double i, double j, double k) {
  double sum = i + j + k;
  return sum;
 }
 public static void main(String[] args) {
  Scanner scan = new Scanner(System.in);
  int a = scan.nextInt();
  int b = scan.nextInt();
  int ret1 = sum(a,b);
  System.out.println(ret1);
  double x = scan.nextDouble();
  double y = scan.nextDouble();
  double z = scan.nextDouble();
  double ret2 = sum(x,y,z);
  System.out.println(ret2);
 }
}