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: Wrong Answer)

#include <bits/stdc++.h>

using namespace std;

/**************************************************************/
#define int          long long
#define mem(a , v)   memset(a , v , sizeof a)
#define all(v)       v.begin() , v.end()
#define ff           first
#define ss           second
#define err(x)       cerr << #x << " is : " << x << endl
#define endl         "\n"



const int MOD   =   1e9 + 7;
const int N     =   1e6 + 20;
const int big   =   1e14;
/***************************************************************/

void solve()
{
    int l , r , m;
    cin >> l >> r >> m;

    int mul = (r - l + 1) / m;

    cout << mul << endl;
    return;
}


int32_t main()
{
    clock_t st = clock();
    ios_base :: sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
   //cin >> t;
    while(t--)
        solve();
    clog<<(long double)((clock() - st)/CLOCKS_PER_SEC)<<endl;
    return 0;
}