Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = input()
lst = [0] * 1000
for i in range(1000):
    if len(str(i)) == 1:
        tmp = '00' + str(i)
        lst[i] = tmp
    elif len(str(i)) == 2:
        tmp = '0' + str(i)
        lst[i] = tmp
    else:
        lst[i] = str(i)

cnt = 0
for v in lst:
    flag = False
    first_key = v[0]
    for i in range(len(s)):
        if s[i] == first_key:
            second_key = v[1]
            for j in range(i + 1, len(s)):
                if s[j] == second_key:
                    third_key = v[2]
                    for k in range(j + 1, len(s)):
                        if s[k] == third_key:
                            flag = True
    if flag:
        cnt += 1

print(cnt)

Fixed submission:
n = int(input())
s = input()
lst = [0] * 1000
for i in range(1000):
    if len(str(i)) == 1:
        tmp = '00' + str(i)
        lst[i] = tmp
    elif len(str(i)) == 2:
        tmp = '0' + str(i)
        lst[i] = tmp
    else:
        lst[i] = str(i)

cnt = 0
for v in lst:
    id_1 = s.find(v[0])
    if id_1 == -1:
        continue
    id_2 = s.find(v[1], id_1 + 1)
    if id_2 == -1:
        continue
    id_3 = s.find(v[2], id_2 + 1)
    if id_3 == -1:
        continue
    cnt += 1

print(cnt)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = input()
lst = [0] * 1000
for i in range(1000):
    if len(str(i)) == 1:
        tmp = '00' + str(i)
        lst[i] = tmp
    elif len(str(i)) == 2:
        tmp = '0' + str(i)
        lst[i] = tmp
    else:
        lst[i] = str(i)

cnt = 0
for v in lst:
    flag = False
    first_key = v[0]
    for i in range(len(s)):
        if s[i] == first_key:
            second_key = v[1]
            for j in range(i + 1, len(s)):
                if s[j] == second_key:
                    third_key = v[2]
                    for k in range(j + 1, len(s)):
                        if s[k] == third_key:
                            flag = True
    if flag:
        cnt += 1

print(cnt)

Fixed submission:
n = int(input())
s = input()
lst = [0] * 1000
for i in range(1000):
    if len(str(i)) == 1:
        tmp = '00' + str(i)
        lst[i] = tmp
    elif len(str(i)) == 2:
        tmp = '0' + str(i)
        lst[i] = tmp
    else:
        lst[i] = str(i)

cnt = 0
for v in lst:
    id_1 = s.find(v[0])
    if id_1 == -1:
        continue
    id_2 = s.find(v[1], id_1 + 1)
    if id_2 == -1:
        continue
    id_3 = s.find(v[2], id_2 + 1)
    if id_3 == -1:
        continue
    cnt += 1

print(cnt)

Buggy python submission (verdict: Time Limit Exceeded):
from itertools import combinations
n = int(input())
s = input()
lst = [0] * 1000
for i in range(1000):
    if len(str(i)) == 1:
        tmp = '00' + str(i)
        lst[i] = tmp
    elif len(str(i)) == 2:
        tmp = '0' + str(i)
        lst[i] = tmp
    else:
        lst[i] = str(i)



com = list(combinations(s, 3))
com = list(set([''.join(x) for x in com]))
cnt = 0
for x in lst:
    if x in com:
        cnt += 1

print(cnt)

Fixed submission:
n = int(input())
s = input()
lst = [0] * 1000
for i in range(1000):
    if len(str(i)) == 1:
        tmp = '00' + str(i)
        lst[i] = tmp
    elif len(str(i)) == 2:
        tmp = '0' + str(i)
        lst[i] = tmp
    else:
        lst[i] = str(i)

cnt = 0
for v in lst:
    id_1 = s.find(v[0])
    if id_1 == -1:
        continue
    id_2 = s.find(v[1], id_1 + 1)
    if id_2 == -1:
        continue
    id_3 = s.find(v[2], id_2 + 1)
    if id_3 == -1:
        continue
    cnt += 1

print(cnt)

Buggy python submission (verdict: Time Limit Exceeded):
from itertools import combinations
n = int(input())
s = input()
num_id = [x for x in range(len(s))]
A = list(combinations(num_id, 3))
B = [s[x[0]] + s[x[1]] + s[x[2]] for x in A]
print(len(set(B)))

Fixed submission:
n = int(input())
s = input()
lst = [0] * 1000
for i in range(1000):
    if len(str(i)) == 1:
        tmp = '00' + str(i)
        lst[i] = tmp
    elif len(str(i)) == 2:
        tmp = '0' + str(i)
        lst[i] = tmp
    else:
        lst[i] = str(i)

cnt = 0
for v in lst:
    id_1 = s.find(v[0])
    if id_1 == -1:
        continue
    id_2 = s.find(v[1], id_1 + 1)
    if id_2 == -1:
        continue
    id_3 = s.find(v[2], id_2 + 1)
    if id_3 == -1:
        continue
    cnt += 1

print(cnt)