The number of even n-digit numbers is 4#9949

The number of even n-digit numbers is 4

1 second
64 megabytes
Easy

It is necessary to find and output the number of even natural -digit numbers that do not belong to the interval .

Input

Three natural numbers , , in one line separated by a space (1 ≤ n ≤ 12), (1 ≤ a,b ​​≤ 10^{12})

Output

The answer to the problem.

Examples

Example 1

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