Conversation with memory + 2 inputs

Hey there! I’m trying to user Conversationchain or LLM Chain with a prompt with 2 inputs + memory, but I cant make it work, does anyone know how to solve this?

prompt = ''' Hello my names is {a} and i work at {b} 
if previous conversation you will have it here:
{memory} ""
llm = ChatOpenAI()
memory = ConversationBufferMemory()
chain = LLMChain(prompt = prompt, llm = llm, memory = memory)
chain.preditc(a='randomname' , b='randomcompany')
ValueError: One input key expected got ['a', 'b']