做两个索引去比较字母,注意每比较一个,flag都要清零
while True: try: str1 = str(input()) for i in range(len(str1)): flag1 = 0 flag2 = 0 for k in range(len(str1)): if(i != k): if(str1[i] == str1[k]): flag1 = 1 break if(flag1 == 0 and k == len(str1)-1): print(str1[i]) flag2 = 1 break if(flag2 == 1): break if(flag2 == 0): print(-1) except: break