let line = readline().split('')

let map = {}

for(let ch of line){
  if(map[ch]) map[ch]++
  else map[ch] = 1
}

let min = Math.min(...Object.values(map))

let result = ''
for(let i=0;i<line.length;i++){
  if(map[line[i]] !== min){
    result+=line[i]
  }
}

console.log(result)