'''
Given a 0-indexed integer array nums, return the smallest index i of nums such that i mod 10 == nums[i], or -1 if such index does not exist.

x mod y denotes the remainder when x is divided by y.

 

Example 1:

Input: nums = [0,1,2]
Output: 0
Explanation: 
i=0: 0 mod 10 = 0 == nums[0].
i=1: 1 mod 10 = 1 == nums[1].
i=2: 2 mod 10 = 2 == nums[2].
All indices have i mod 10 == nums[i], so we return the smallest index 0.
Example 2:

Input: nums = [4,3,2,1]
Output: 2
Explanation: 
i=0: 0 mod 10 = 0 != nums[0].
i=1: 1 mod 10 = 1 != nums[1].
i=2: 2 mod 10 = 2 == nums[2].
i=3: 3 mod 10 = 3 != nums[3].
2 is the only index which has i mod 10 == nums[i].
Example 3:

Input: nums = [1,2,3,4,5,6,7,8,9,0]
Output: -1
Explanation: No index satisfies i mod 10 == nums[i].
 

Constraints:

1 <= nums.length <= 100
0 <= nums[i] <= 9
'''
from typing import *

import unittest


class Solution:
    def smallestEqual(self, nums: List[int]) -> int:
        for i in range(len(nums)):
            if i % 10 == nums[i]:
                return i
        return -1
        

class TestSolution(unittest.TestCase):

    def test_case(self):
        examples = (
            (([4,3,2,1],),2),
        )
        for first, second in examples:
            self.assert_function(first, second)

    def assert_function(self, first, second):
        self.assertEqual(Solution().smallestEqual(*first), second,
                         msg="first: {}; second: {}".format(first, second))


unittest.main()