Kata

You are given a series of input.

Task
Your task is to write a BF program in which will output a string with the first input in front and in between every other value that should exclude the first value and stop when input == first_input or input == null.

When to Stop?
Your program should stop outputting the value when it meets the same value as the first input or until the end of the input if it is nowhere to be found.

Example

'1b393\0'     -->     '1b1319131'       #No duplicate input
'13a135\0'    -->     '131a1'           #Input == first_input after 'a'
'aaa\0'       -->     'a'               #All duplicate input
'1\0'         -->     '1'               #Input length == 1
'\0'          -->     ''                #Input length == 0

Note

• Every input will be a string
• The input will contain ASCII values in range 32-127
• Input length constrain 0 <= input length <= 50
• Every input will end with a null character