Number of Unique Passwords after Repeated Permutations

def perm(str1):
    L1 = list(str1)
    str2 = ""
    res = []

    for i in range(len(L1)):
        for j in range(len(L1)):
            if (i+j)%2 == 0:
                temp = L1[i]
                L1[i] = L1[j]
                L1[j] = temp

                for k in L1:
                    str2 += k
                else:
                    if str2 not in res:
                        res.append(str2)
                        str2 = ""
                    else:
                        str2=""

    res.remove(str1)

    return res

def no_unique_pass(arr):
    no_uni_pass = 1
    L1_res = []

    for i in arr:
        res = perm(i)
        j = 0

        while j < len(arr):
            if bool(res.count(arr[j])):
                del arr[j]

            j += 1

    else:
        no_uni_pass += (len(arr) - 1)

    return no_uni_pass

def main():
    L1 = []

    n = int(input("Enter the Number of Users : "))
    print("\nEnter the Users' password one-by-one...")

    for i in range(n):
        password = input("Enter the Password : ")
        L1.append(password)

    unique_pass = no_unique_pass(L1)

    print("Number of Unique Passwords : ", unique_pass)

main()