Reactor Core Output Level

A test reactor's core output level starts at 0. Engineers issue a sequence of n control commands to the console one after another; each command is written as exactly one of four strings: ++PWR, PWR++, --PWR, or PWR--. Regardless of whether the ++ or -- symbol appears before or after PWR, a command containing ++ raises the output level by 1, and a command containing -- lowers it by 1.

Given the full sequence of commands in the order they were issued, determine the reactor's output level after all of them have been applied.

Input format

• Line 1: an integer n, the number of commands.
• Line 2: n space-separated tokens, each command in the order given.

Output format

Print a single integer: the final output level.

Constraints

• 1 <= n <= 100
• Each command is exactly one of the strings ++PWR, PWR++, --PWR, PWR--.

4
++PWR PWR++ --PWR PWR++

2

3
--PWR --PWR --PWR

-3