Need help with formula to determine if two names appear together in a column

Hi,

I'm working on building a spreadsheet to track the results of a friendship survey completed by elementary school students. I'm trying to build a formula that will determine if two names appear together in a column (friendship group). A brief sample of how entries would look:

A B C D
1 Mike Sara Steve Chad
2 Ryan Owen Chad Steve
3 Steve David Owen Sara
4 Sara Kate Mike Mike

The formula I need help with would determine how many times a particular student is endorsed as belonging to the same friendship group as a peer. For example, in how many columns "Mike" appears with "Sara."

Any help would be greatly appreciated!

Thanks!