05.Account Balance - while - loops

function accountBalance(input) {
    let transactionCount = Number(input.shift());
    let balance = 0;
    let counter = 1;



    while (transactionCount >= counter) {
        let num = Number(input.shift());
    if (num < 0) {
        console.log("Invalid operation!");
        break;
    }
        balance += num;

        console.log(`Increase: ${num.toFixed(2)}`);
        counter++;
    }
    console.log(`Total: ${balance.toFixed(2)}`);
}