str = input()
maxStr = "";   #存放长度最长的单词
k = 0          #存放最长单词的长度      
li = str.split(" ");
for i in range(0,len(li)):
    f = True
    for j in range(i + 1,len(li)):
        if len(li[i]) < len(li[j]):
            f = False;
            x = 1
            break;
    if f:
      print(li[i])
      break;



/**************************************************************
	Problem: 1107
	User: admin
	Language: Python
	Result: Accepted
	Time:99 ms
	Memory:34480 kb
****************************************************************/