Is it a MD5 hash?
I have a set of input and output data.

Input: 1900
Output: 10339a1efa428511e44bccb4031ee11e

Input: 0
Output: 0151d34b712c525b812a3cd7ac58c9ec

Input: 1500
Output: 10b09226e0bd5b6e823be378b1ef6f33

The output is always 32 char long.

I guess the input value was hashed with MD5 with following piece of javascript code:

Can anyone tell what actually it is doing, thanks a lot!
1. you should be very careful to post hashes here, because it is not allowed according to the forum rules, see for instance
2. since you provided the plain text and some "code", I think we could make an exception and don't ban you, but next time please ask first about the problem and provide the information/code. Only after approvement of the Admin or Moderators, you should post hashes.

3. this seems to be very easy to solve, it is just:
salt = "=FLK324956yhl%$==key=Fnwer295*(&*(&%214=gsidk=IAFhioqwr21402814;f=vm349" (without codes)
algorithm = -m 10 = md5 ($pass . $salt)

for instance if pass = "1900" (without quotes):
echo -n '1900=FLK324956yhl%$==key=Fnwer295*(&*(&%214=gsidk=IAFhioqwr21402814;f=vm349' | md5sum

If pass = "0" (w/o quotes):
echo -n '0=FLK324956yhl%$==key=Fnwer295*(&*(&%214=gsidk=IAFhioqwr21402814;f=vm349' | md5sum


BTW: the salt is way too long for hashcat/oclHashcat, it is horrible long and not supported, but the algorithm is like -m 10 = md5 ($pass . $salt)