let line = readline(); let map = {}; for (let i = 0; i < line.length; i++) { if (map[line[i]]) map[line[i]]++ else map[line[i]] = 1 } let mapArr = Object.entries(map); mapArr.sort((a, b) => b[1] === a[1] ? a[0].charCodeAt() - b[0].charCodeAt() : b[1] - a[1]) print(mapArr.reduce((a, b) => a + b[0], ''))