function solve(input) {

  let num = input.shift();

  num = Number(num);

  let j = 0;

  let arr = [];


  for (let i = 0; i < num; i++) {

    let curEl = input.shift().split('|');

    arr.push({ piece: curEl[0], composer: curEl[1], key: curEl[2] });

  }

  // console.log(arr);


  while (input[j] !== 'Stop') {

    let curEl = input[j].split('|');

    let command = curEl[0];


    if (command === 'Add') {

      if (arr.some(el => el.piece === curEl[1])) {

        console.log(`${curEl[1]} is already in the collection!`);

      } else {

        arr.push({ piece: curEl[1], composer: curEl[2], key: curEl[3] });

        console.log(`${curEl[1]} by ${curEl[2]} in ${curEl[3]} added to the collection!`);

      }

    } else if (command === 'Remove') {

      if (arr.some(el => el.piece === curEl[1])) {

        let index = 0;

        arr.forEach(el => el.piece === curEl[1] ? index = arr.indexOf(el) : false);

        arr.splice(index, 1);

        console.log(`Successfully removed ${curEl[1]}!`);

      } else {

        console.log(`Invalid operation! ${curEl[1]} does not exist in the collection.`);

      }


    } else if (command === 'ChangeKey') {

      if (arr.some(el => el.piece === curEl[1])) {

        arr.forEach(el => el.piece === curEl[1] ? el.key = curEl[2] : false);

        console.log(`Changed the key of ${curEl[1]} to ${curEl[2]}!`);

      } else {

        console.log(`Invalid operation! ${curEl[1]} does not exist in the collection.`);

      }

    }

    j++;
  }


  arr.sort((a, b) => a.piece.localeCompare(b.piece));


  for (let el of arr) {

    console.log(`${el.piece} -> Composer: ${el.composer}, Key: ${el.key}`);

  }



}