“运行总计返回错误值”

因此，此代码应该将每一天的总和相加并显示总销售额

但是由于某种原因，答案始终是天数的平方

我以为这是由于其他Java文件打开导致的，所以我删除了它们，但没有帮助

package com.test;

import javax.swing.*;

public class test_3
{
    public static void main(String[] args)
    {
        int days;                       //number of days
        double sales;                  // sales per day
        double TotalSales = 0.0;       // Total sales

        String input = JOptionPane.showInputDialog("For how many days is the sales ?");

        days = Integer.parseInt(input);         //converting days into number

        for(int count = 1; count <= days; count++)
        {
            JOptionPane.showInputDialog("Enter sales amount of day " + count);
            sales = Double.parseDouble(input);

            TotalSales += sales;
        }

        JOptionPane.showMessageDialog(null,"Total sales is "+ TotalSales);


    }
}

我该怎么办 ？