Between A and B#8594

Between A and B

1 second
128 megabytes
Easy

Given nonnegative integers and b~(a \le b) and positive integer . How many numbers are there between and inclusively, divisible by ?

Input

Three numbers and x~(0 \le a \le b \le 10^{18}, 1 \le x \le 10^{18}).

Output

Print the answer to the problem.

Examples

Example 1

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