Problem:
Score : 100 points

Problem Statement

How many multiples of d are there among the integers between L and R (inclusive)?

Constraints

All values in input are integers.

1 \leq L \leq R \leq 100

1 \leq d \leq 100

Input

Input is given from Standard Input in the following format:

L R d

Output

Print the number of multiples of d among the integers between L and R (inclusive).

Sample Input 1

5 10 2

Sample Output 1

3

Among the integers between 5 and 10, there are three multiples of 2: 6, 8, and 10.

Sample Input 2

6 20 7

Sample Output 2

2

Among the integers between 6 and 20, there are two multiples of 7: 7 and 14.

Sample Input 3

1 100 1

Sample Output 3

100

Solution in Rust (1.42.0) (judge verdict: Accepted)

#![allow(
    non_snake_case,
    unused_variables,
    unused_assignments,
    unused_mut,
    dead_code
)]
//use proconio::fastout;
use proconio::input;
//use proconio::marker::*;
//use std::collections::HashSet;
// use std::cmp::*;
//use std::collections::VecDeque;

fn main() {
    input! {
       L:i64,R:i64,d:i64
    }

    //println!("{}", R / d);
    //println!("{}", (L + d - 1) / d);
    println!("{}", (R / d - (L + d - 1) / d) + 1);
}