How to find Maximum Value of Multiple Properties

How to find Maximum Value of Multiple Properties

We have the following Product Class.
public string Product{ get; set; }
public int? Monday { get; set; }
public int? Tuesday { get; set; }
public int? Wednesday { get; set; }
public int? Thursday { get; set; }
public int? Friday { get; set; }
public int? Saturday { get; set; }
public int? Sunday { get; set; }
public string Zip { get; set; }
The Properties hold the sales values for that day of the week. We need to
be able to search a list of Products, and select the Total Sales for ALL
products based on the Product's best sales day. For instance: In the
sample below, product 1 has the highest sales on Monday and Product2 has
the highest sales on Sunday, so the total should combine the 2 (5378).
Product Zip City State Sunday Monday Tuesday Wednesday
Thursday Friday
Product 1 63103 Saint Louis MO 0 4728 0 1522 0 0
Product 2 63103 Saint Louis MO 650 419 417 428 599 559
Here is the LINQ code I have so far.
var temp = report.SelectMany(p => p.SnapshotRecords)
.Where(record => record.Zip == "63103")
.GroupBy(g => new
{
g.Zip,
g.ProductID
})
.Select(s => new SnapshotData()
{
Monday = s.Sum(g => g.Monday),
Tuesday = s.Sum(g => g.Tuesday),
Wednesday = s.Sum(g => g.Wednesday),
Thursday = s.Sum(g => g.Thursday),
Friday = s.Sum(g => g.Friday),
Saturday = s.Sum(g => g.Saturday),
Sunday = s.Sum(g => g.Sunday),
});