const longestPalindrome = s => {
    const symbolsHashMap = new Map();

    for (let i = 0; i < s.length; i++) {
        const symbolsCount = symbolsHashMap.get(s[i]);
        if(!symbolsCount) {
            symbolsHashMap.set(s[i], 1);
        } else {
            symbolsHashMap.set(s[i], symbolsCount + 1);
        }
    }

    let maxNotEven = 0;
    let evenSymbols = 0;
    symbolsHashMap.forEach((item) => {
        if(item % 2 === 0) {
            evenSymbols += item;
        } else if(item > maxNotEven) {
            maxNotEven = item;
        }
    })

    // console.log(maxNotEven);
    // console.log(symbolsHashMap);

    return evenSymbols + maxNotEven;
};