problem

A mysterious $ X $ [cm] plant grows in one place. This plant has the following mysterious properties.

• Say "nobiro" to this plant and it will grow $ A $ [cm].
• Say "tidime" to this plant and it will grow $ B $ [cm].
• If you say "karero" to this plant, it will be $ 0 $ [cm].

However, this plant does not have a negative length. Specifically, when it grows from the state of $ C $ [cm] to $ D $ [cm] $(C + D \ lt 0)$, it is a plant. Stops growing when it reaches $ 0 $ [cm].

Say one of "nobiro", "tidime", "karero" to this plant only once a day for $ N $ days. Find the length [cm] of the plant after $ N $ days.

output

Print the length of the plant after $ N $ days. Also print a newline at the end.

Example

Input

10 30 10
3
nobiro
nobiro
tidime

Output

80

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