7116번 - Series 다국어

문제

All the natural numbers from n to m (inclusively) are written in a row without separating symbols, thus creating a series of decimal digits.

For example, if n=98 and m=102, this series is 9899100101102.

Then all the digits are sorted in a non-increasing order - first the greatest digits, then the next greatest, etc.

For the example above this sorted series is 9998211110000.

For the values of natural numbers n,m and k given in the input your task is to compute, which digit will be in the k-th position of the sorted series.

입력

The values of three natural numbers n (0 < n < 10⁹), m (0 < m < 10⁹, m ≥ n) and k (0 < k < 10⁹) are input from the keyboard.

출력

The digit at the k-th position of the sorted series must be output on the screen. If length of the series is less than k, a single word “NAV” must be output on the screen.

제한

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