Osajono

#!/usr/bin/python3
from collections import Counter
from math import factorial

def nCk(n,k): 
  return factorial(n) // factorial(k) // factorial(n-k)


a=input()
b=len(a)
#c=0
d=0
#for i in range(0,b):
#	for j in range(i,b):
		#print(a[i:j+1])
#		if a[i:j+1][0] == a[i:j+1][-1]:
#			c+=1

counter = Counter(a)
for i in list(counter.values()):
	d+=nCk(i,2)
d+=b
#print(counter.values())
print(d)

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 21, in <module>
    d+=nCk(i,2)
  File "input/code.py", line 6, in nCk
    return factorial(n) // factorial(k) // factorial(n-k)
ValueError: factorial() not defined for negative values

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED