PROGRAMMING:Alternate arrangement of soft and hard cars
There are n hard seat cars and soft seat cars (mixed together) produced by a vehicle factory. It is required to use the basic operation of queue and program to realize the alternate arrangement of all hard seat cars and all soft seat cars. For example, the hard seat carriage is represented by H, and the soft seat carriage is represented by S. input the code of 8 carriages from the keyboard as shhsss, and output as HSSs. If the code of 8 cars is shhshhsh, the output is hshh.
###Input format:
In the first line, enter the number of cars shared by hard seat and soft seat cars, 2 < = number of cars < = 10;
In the second line, enter the car code according to the number of cars.
###Output format:
If the number of cars exceeds the legal range, output "error", otherwise output the result of alternating arrangement of H and s cars, and note that the output result begins with H.
###Input example:
```in
eight
SHHSSHSS
```
###Output example:
```out
HSHSHSSS
```
answer：If there is no answer, please comment
###Input format:
In the first line, enter the number of cars shared by hard seat and soft seat cars, 2 < = number of cars < = 10;
In the second line, enter the car code according to the number of cars.
###Output format:
If the number of cars exceeds the legal range, output "error", otherwise output the result of alternating arrangement of H and s cars, and note that the output result begins with H.
###Input example:
```in
eight
SHHSSHSS
```
###Output example:
```out
HSHSHSSS
```
answer：If there is no answer, please comment