How to properly remove an element from an array?

Question

JavaScript

it is necessary that the last letter from the array is removed on 'c'.
I did everything as on the Internet, then 2 elements then appear. In general, I did not really find anything. Help I'm just learning

let a = document.querySelector('.a'),
    b =  document.querySelector('.b'),
    c =  document.querySelector('.c');

let array = [a,b]

let pup = []
for (let element of array) {
    element.addEventListener('click', ()=>{
        pup.push(element.value)
        let input = document.querySelector('.input')

        input.value = pup.join('')
        c.addEventListener('click', ()=>{
            
        })
    })
}

tried filter shift pop splice apparently did something wrong))

Answer 1

const a = document.querySelector('.a'),
    b =  document.querySelector('.b'),
    c =  document.querySelector('.c');
const input = document.querySelector('.input')
const array = [a,b,c]

let pup = []
for (let element of array) {
    element.addEventListener('click', ({target})=>{
        if(['a','b'].includes(target.value)) {
          pup.push(target.value)
        } else {
          pup.pop()
        }
        input.value = pup.join('')
    })
}

Answer 2

https://codesandbox.io/s/awesome-pond-e176yh
I don't know if you have this in mind, but you hang up the handler on "c" only after clicking on one of the elements, this also needs to be taken into account.