package main

import "bufio"
import "fmt"
import "os"

type RuneList struct {
    runes map[rune]int
}

type Code struct {
    runes [8]RuneList
}

func (this *RuneList) AppendRune(in rune) {
    this.runes[in]++
}

func (this RuneList) GetBest() rune {
    var bestRune rune
    bestInt := 0

    for i, j := range(this.runes) {
        if j > bestInt {
            bestInt = j
            bestRune = i
        }
    }
    return bestRune
}

func (this RuneList) GetWorst() rune {
    var bestRune rune
    bestInt := len(this.runes)

    for i, j := range(this.runes) {
        if j < bestInt {
            bestInt = j
            bestRune = i
        }
    }
    return bestRune
}

func NewRuneList() RuneList {
    var r RuneList
    r.runes = make(map[rune]int)
    return r
}

func (this *Code) Append(in string) {
    for i := 0; i < 8; i++ {
        this.runes[i].AppendRune(rune(in[i]))
    }
}

func (this Code) GetBest() string {
    var result string

    for i := 0; i < 8 ; i++ {
        result += string(this.runes[i].GetBest())
    }
    return result
}

func (this Code) GetWorst() string {
    var result string

    for i := 0; i < 8 ; i++ {
        result += string(this.runes[i].GetWorst())
    }
    return result
}

func NewCode() Code {
    var this Code
    for i :=0; i < 8; i++ {
        this.runes[i] = NewRuneList()
    }
    return this
}

func main() {
    reader := bufio.NewReader(os.Stdin)
    codeList := NewCode()

    for true {
        line, err := reader.ReadString('\n')
        if len(line) == 9 {
            line = line[0:len(line) -1]
            codeList.Append(line)
        }
        if err != nil {
            break
        }
    }

    result := codeList.GetWorst()
    fmt.Println(result)
}