Buggy python submission (verdict: Time Limit Exceeded):
import itertools

iCnt = int(input())
v = list(input())

vAns = []
vProduct = []
iOnIndex = 0
for _ in range(iCnt - 1):
    iLen = len(v[-iCnt + iOnIndex + 1:])
    vProduct = itertools.product([0, 1], repeat=iLen)
    for p in vProduct:
        sChk = v[iOnIndex]
        iP_Len = len(p)
        for i in range(iP_Len):
            if p[i] == 1:
                if v[iOnIndex + i + 1] not in sChk:
                    sChk += v[iOnIndex + i + 1]
                else:
                    sChk = "NG"
                    break
        if "NG" not in sChk: vAns.append(sChk)
    iOnIndex += 1
vAns.append(v[iCnt - 1])
print(len(vAns) % (10 ** 9 + 7))

Fixed submission:
from collections import defaultdict

iCnt = int(input())
S = input()
M = 10**9 + 7

vCntDct = defaultdict(int)

for s in S:
    vCntDct[s] += 1

ans = 1
for v in vCntDct.values():
    ans *= (v + 1)
    ans %= M

print(ans - 1)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools

iCnt = int(input())
v = list(input())

vAns = []
vProduct = []
iOnIndex = 0
while iOnIndex + 1 < iCnt:
    iLen = len(v[-iCnt + iOnIndex + 1:])
    vProduct = list(itertools.product([0, 1], repeat=iLen))
    for p in vProduct:
        sChk = v[iOnIndex]
        iP_Len = len(p)
        for i in range(iP_Len):
            if p[i] == 1:
                if v[iOnIndex + i + 1] not in sChk:
                    sChk += v[iOnIndex + i + 1]
                else:
                    sChk = "NG"
                    break
        if "NG" not in sChk: vAns.append(sChk)
    iOnIndex += 1
vAns.append(v[iCnt - 1])
print(len(vAns) % (10 ** 9 + 7))

Fixed submission:
from collections import defaultdict

iCnt = int(input())
S = input()
M = 10**9 + 7

vCntDct = defaultdict(int)

for s in S:
    vCntDct[s] += 1

ans = 1
for v in vCntDct.values():
    ans *= (v + 1)
    ans %= M

print(ans - 1)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools

iCnt = int(input())
v = list(input())

vAns = []
vProduct = []
iOnIndex = 0
while iOnIndex + 1 < iCnt:
    iLen = len(v[-iCnt + iOnIndex + 1:])
    vProduct = list(itertools.product([0, 1], repeat=iLen))
    for p in vProduct:
        sChk = v[iOnIndex]
        iP_Len = len(p)
        for i in range(iP_Len):
            if p[i] == 1:
                if v[iOnIndex + i + 1] not in sChk:
                    sChk += v[iOnIndex + i + 1]
                else:
                    sChk = "NG"
                    break
        if "NG" not in sChk: vAns.append(sChk)
    iOnIndex += 1
vAns.append(v[iCnt - 1])
print(len(vAns) % (10 ** 9 + 7))

Fixed submission:
from collections import defaultdict

iCnt = int(input())
S = input()
M = 10**9 + 7

vCntDct = defaultdict(int)

for s in S:
    vCntDct[s] += 1

ans = 1
for v in vCntDct.values():
    ans *= (v + 1)
    ans %= M

print(ans - 1)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools

iCnt = int(input())
v = list(input())

vAns = []
vProduct = []
iOnIndex = 0
while iOnIndex + 1 < len(v):
    iLen = len(v[-len(v) + iOnIndex + 1:])
    vProduct = list(itertools.product([0, 1], repeat=iLen))
    for p in vProduct:
        sChk = v[iOnIndex]
        for i in range(len(p)):
            if p[i] == 1:
                if v[iOnIndex + i + 1] not in sChk:
                    sChk += v[iOnIndex + i + 1]
                else:
                    sChk = "NG"
                    break
        if "NG" not in sChk: vAns.append(sChk)
    iOnIndex += 1
vAns.append(v[len(v) - 1])
print(len(vAns) % (10 ** 9 + 7))

Fixed submission:
from collections import defaultdict

iCnt = int(input())
S = input()
M = 10**9 + 7

vCntDct = defaultdict(int)

for s in S:
    vCntDct[s] += 1

ans = 1
for v in vCntDct.values():
    ans *= (v + 1)
    ans %= M

print(ans - 1)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools

iCnt = int(input())
v = list(input())

vAns = []
vProduct = []
iOnIndex = 0
while iOnIndex + 1 < len(v):
    iLen = len(v[-len(v) + iOnIndex + 1:])
    vProduct = list(itertools.product([0, 1], repeat=iLen))
    for p in vProduct:
        sChk = v[iOnIndex]
        for i in range(len(p)):
            if p[i] == 1:
                if v[iOnIndex + i + 1] not in sChk:
                    sChk += v[iOnIndex + i + 1]
                else:
                    sChk = "NG"
        if "NG" not in sChk: vAns.append(sChk)
    iOnIndex += 1
vAns.append(v[len(v) - 1])
print(len(vAns) % (10 ** 9 + 7))

Fixed submission:
from collections import defaultdict

iCnt = int(input())
S = input()
M = 10**9 + 7

vCntDct = defaultdict(int)

for s in S:
    vCntDct[s] += 1

ans = 1
for v in vCntDct.values():
    ans *= (v + 1)
    ans %= M

print(ans - 1)