The 74LSxx chip family is a collection of discrete logic ICs, like logic gates, flip-flops, counters etc. But what are your options if you can’t find a specific 74LS chip? You can replace it using RDT-TTL5V-14 Programmable TTL digital logic gate. RDT-TTL5V-14 can be configured to any 74LS discrete logic gate function offered in a 14-pin DIP package footprint.
Programmable TTL digital logic gate - [Link]