time limit per test: 0.25 sec. memory limit per test: 4096 KB
input: standard output: standard
Let us call P(n) - the product of all digits of number n (in decimal notation). For example, P(1243)=1*2*4*3=24; P(198501243)=0. Let us call n to be a good number, if (p(n)<>0) and (n mod P(n)=0). Let us call n to be a perfect number, if both n and n+1 are good numbers.
You are to write a program, which, given the number K, counts all such numbers n that n is perfect and n contains exactly K digits in decimal notation.
Only one number K (1<=K<=1000000) is written in input.
Output the total number of perfect k-digit numbers.
All-Russian mathematical olympiad jury
District mathematical olympiad, 8th form
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