import re

ser = re.search(r'([a-zA-Z0-9])\1',input()) if ser: print(ser.group()[0]) else: print(-1)

1. import re
2. 3. ser = re.search(r'([a-zA-Z0-9])\1',input())
3. if ser:
4. print(ser.group()[0])
5. else:
6. print(-1)

1. n = input()
2. li = "1234567890abcdefghijkelmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
3. for i in range(len(n)-1):
4. if n[i]==n[i+1] and n[i] in li :
5. print(n[i])
6. break
7. else:
8. print(-1)

• inpt = input()
• l = []
• res = []
• p = []
• last = []
• for i in inpt:
• if i.isalnum():
• l.append(i)
• for i in range(len(l)-1):
• if l[i] == l[i+1]:
• res.append(i)
• res = list(map(str,res))
• for rev in res:
• b = reversed(rev)
• p.append(''.join(b))
• for i in range(len(res)-1):
• if res[i] == p[i]:
• last.append(res[i])
• if len(last) >0:
• print(last[0][0])
• elif len(last) == 0:
• print(-1)
*