Ositus

string = input()
mod = int(1e9+7)
ans = ((1 << (len(string)-1)) - 1) % mod


def finder(string, ch, count):
    x = []
    cuts = 0
    for i in range(count):
        x1 = string.find(ch)+cuts
        string = string[x1+1:]
        cuts += x1 + 1
        x.append(x1)

    return x

# Periaatteellinen vika looperissa!
# esim merkkijonon "axbxcx" tapauksessa:
# jaettu merkkijono "a|xbxcx" miinustetaan kolmesti yhden kerran sijaan.


def looper(x: str, length, mod):
    sum = 0
    for i in range(len(x)):
        for j in range(len(x)):
            if j > i:
                sum = (sum + (1 << (x[i]-x[j]+length-1)) - 1) % mod
    return sum


for ch in ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "m", "n", "l", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"]:
    if string.count(ch) > 1:
        count = string.count(ch)
        if count > 1:
            x = finder(string, ch, count)
            ans -= looper(x, len(string), mod)

print(ans)

Test 1

Group: 1, 2, 3

Verdict: WRONG ANSWER

Test 2

Group: 1, 2, 3

Verdict: WRONG ANSWER

Test 3

Group: 1, 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 36, in <module>
    ans -=...

Test 4

Group: 1, 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 36, in <module>
    ans -=...

Test 5

Group: 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 36, in <module>
    ans -=...

Test 6

Group: 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 36, in <module>
    ans -=...

Test 7

Group: 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 36, in <module>
    ans -=...