class Solution(object):
    def findNthDigit(self, n):
        """
        :type n: int
        :rtype: int
        """
        shift = 1
        base = 9 * shift * (10**(shift-1))

        while n > base and shift < 9:
            n -= base
            shift += 1
            base = 9 * shift * (10**(shift-1))

        b = 10**(shift-1) + n // shift
        r = n % shift

        if r == 0:
            b -= 1
            return int(str(b)[-1])

        return int(str(b)[r-1])