If 'P' stands for '$$\times$$', 'Q' stands for '$$\div$$', 'R' stands for '-' and 'S' stands for '+', what will come in place of question mark '?' in the following equation?

15 P 6 R 11 P 4 S 38 R 41 S 2 P 5 = ?

Given: 

'P' stands for  $$\times$$​'',

'Q' stands for '$$\div$$',

'R' stands for '-'

'S' stands for '+', 

15 P 6 R 11 P 4 S 38 R 41 S 2 P 5 = ?

After interchanging the sing we get following equation - 

15 $$\times$$​ 6 - 11 $$\times$$​ 4 + 38 - 41 + 2 $$\times$$​ 5 = ?

90 - 44 + 38 - 41 + 10 = ?

138 - 85 = ?

53 = ?