In this task you will be given an arithmetic operation and you have to find its answer. The symbols of operators '+' and '-' has been swapped i.e you need to perform subtraction when you see a '+' symbol and  addition in case of '-' symbol.
Q: 6879 + 387 + 5118 + 1149 + 4126 - 7405 - 8680 - 8071
A: 
20255