function pianist (input){
let pianistsList = {}
let PianistLine=input.splice(0,input.shift()).map(line=>{
    [piece,composer , key ] = line.split("|")
    if(!pianistsList.hasOwnProperty(piece))
        pianistsList[piece] = {composer, key}
})
let comandLine = input.splice(0, input.indexOf("Stop")).map(line=>{let [command, a, b,c] = line.split("|")
switch(command){ case "Add" : add(a,b,c); break;
case "Remove":remove(a); break;
case "ChangeKey":change (a,b); break;}
})
function add(a,b,c){ !pianistsList.hasOwnProperty(a)? (pianistsList[a]={composer: b, key: c,},
      console.log (`${a} by ${b} in ${c} added to the collection!`)):console.log(`${a} is already in the collection!`)}
    function remove(a){ pianistsList.hasOwnProperty(a)?(delete pianistsList[a],
        console.log(`Successfully removed ${a}!`)):console.log(`Invalid operation! ${a} does not exist in the collection.`)}
    function change (a,b){pianistsList.hasOwnProperty(a)?(pianistsList[a].key = b,
        console.log(`Changed the key of ${a} to ${b}!`)):(console.log(`Invalid operation! ${a} does not exist in the collection.`))}

    for (let key in pianistsList){console.log(`${key} -> Composer: ${pianistsList[key].composer}, Key: ${pianistsList[key].key}`)}
    }