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 C (GCC 9.2.1) (judge verdict: Accepted)

//Atcoder AISing Programing Contest 172 A問題

#include <stdio.h>

int main(void) {
    int l, r, d;
    int ceil, bottom, answer;

    scanf("%d", &l);
    scanf("%d", &r);
    scanf("%d", &d);

    ceil = r / d;
    bottom = (l - 1) / d;

    answer = ceil - bottom;

    printf("%d", answer);

    return 0;
}