var dic = [String:Int]()

var mx = 0
var ans:String = ""
for i in 0...2 {
    let num = readLine()!
    if(dic[num] != nil) {
        dic[num]!+=1
    } else {
        dic[num] = 0
    }
    if(mx<dic[num]!) {
        mx = dic[num]!
        ans = num
    }
}

print(ans)