/**
 * @param {number[]} answers
 * @return {number}
 */
var numRabbits = function(answers) {
    const answerCount = new Map();
    for (const answer of answers) {
        let count = answerCount.has(answer) ? answerCount.get(answer) : 0;
        answerCount.set(answer, count + 1);
    }
    let minRabbits = 0;
    for (const [answer, count] of answerCount.entries()) {
        const groupSize = answer + 1;
        const groupCount = Math.ceil(count / groupSize);
        minRabbits += groupCount * groupSize;
    }
    return minRabbits;
};