// =====================
// Forward translation: letters → symbols
// + per-word palindrome
// + multiline palindrome (center = last input line)
// =====================
function forward(input) {
    const map = {
        // Cyrillic
        'Й':'ꖌ','Ц':'⧮','У':'✧','К':'✻','Е':'🜊','Н':'⊞',
        'А':'⛋','Б':'⧲','В':'𖢌','Г':'🮻','Д':'🟗','Ё':'🜋',
        'Ж':'𐋅','З':'᪥','І':'∣','И':'∣','Л':'◇','М':'✸',
        'О':'Ⓞ','П':'☐','Р':'🝊','С':'⯏','Т':'✢','Ў':'✦',
        'Ф':'𖥠','Х':'ꕤ','Ч':'⑄','Ш':'◫','Щ':'⎅','Ъ':'❂',
        'Ы':'∣❁∣','Ь':'❁','Э':'𖡛','Ю':'𖥤','Я':'ⵙ',

        // Latin
        'A':'⛋','B':'𖢌','C':'⯏','D':'🟗','E':'🜊','F':'𖥠',
        'G':'Ⱉ','H':'⊞','I':'ⵙ','J':'𐫰','K':'✻','L':'◇',
        'M':'✸','N':'𑽇','O':'Ⓞ','P':'🝊','Q':'¤','R':'⦻',
        'S':'𖧷','T':'✢','U':'𐫱','V':'🟅','W':'🟏','X':'ꕤ',
        'Y':'✧','Z':'🝱',

        // Digits
        '0':'ⵔ','1':'꞉','2':'⋮','3':'⁘','4':'⸭',
        '5':'⠿','6':'፨','7':'❋','8':'𐧾','9':'ⵔ'
    };

    const lines = input.split('\n');

    const convertedLines = lines.map(line => {
        const words = line.split(/(\s+)/);
        return words.map(word => {
            if (/^\s+$/.test(word)) return word;

            const symbols = Array.from(word.toUpperCase()).map(c => map[c] || c);
            if (!symbols.length) return '';

            const MOM = symbols[0];
            const XMMX = symbols.slice(1);

            return XMMX.slice().reverse().join('') + MOM + XMMX.join('');
        }).join('');
    });

    // Multiline palindrome: mirror around LAST input line
    const reversed = convertedLines.slice().reverse();
    return [...reversed, ...convertedLines.slice(1)].join('\n');
}

// =====================
// Backward translation: symbols → letters
// (undo per-word palindrome + multiline palindrome)
// =====================
function backward(input) {
    const reverseMap = {
        // Cyrillic
        'ꖌ':'Й','⧮':'Ц','✧':'У','✻':'К','🜊':'Е','⊞':'Н',
        '⛋':'А','⧲':'Б','𖢌':'В','🮻':'Г','🟗':'Д','🜋':'Ё',
        '𐋅':'Ж','᪥':'З','∣':'І','◇':'Л','✸':'М','Ⓞ':'О',
        '☐':'П','🝊':'Р','⯏':'С','✢':'Т','✦':'Ў','𖥠':'Ф',
        'ꕤ':'Х','⑄':'Ч','◫':'Ш','⎅':'Щ','❂':'Ъ','∣❁∣':'Ы',
        '❁':'Ь','𖡛':'Э','𖥤':'Ю','ⵙ':'Я',

        // Latin
        '⛋':'A','𖢌':'B','⯏':'C','🟗':'D','🜊':'E','𖥠':'F',
        'Ⱉ':'G','⊞':'H','ⵙ':'I','𐫰':'J','✻':'K','◇':'L',
        '✸':'M','𑽇':'N','Ⓞ':'O','🝊':'P','¤':'Q','⦻':'R',
        '𖧷':'S','✢':'T','𐫱':'U','🟅':'V','🟏':'W','ꕤ':'X',
        '✧':'Y','🝱':'Z'
    };

    const lines = input.split('\n');

    // Only the center line contains the original data
    const centerIndex = Math.floor(lines.length / 2);
    const centerLine = lines[centerIndex];

    const words = centerLine.split(/(\s+)/);

    return words.map(word => {
        if (/^\s+$/.test(word)) return word;

        let decoded = '';
        let remaining = word;

        const keys = Object.keys(reverseMap).sort((a,b) => b.length - a.length);

        while (remaining.length) {
            let matched = false;
            for (const k of keys) {
                if (remaining.startsWith(k)) {
                    decoded += reverseMap[k];
                    remaining = remaining.slice(k.length);
                    matched = true;
                    break;
                }
            }
            if (!matched) {
                decoded += remaining[0];
                remaining = remaining.slice(1);
            }
        }

        const mid = Math.floor(decoded.length / 2);
        return (decoded[mid] + decoded.slice(mid + 1)).toUpperCase();
    }).join('');
}