// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(int X, int Y, int D) {
        // write your code in Java SE 8
    }
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return (x)
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return ()
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return (Y-X)
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return (Y-X/)
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return Math.ceil((Y-X)/D)
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return Math.ceil((Y-X)/D)
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return Math.ceil((Y-X)/D)
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return Math.ceil((Y-X)/D)
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return Math.ceil((Y-X)/D)
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return Math.ceil((Y-X)/D)
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return Math.ceil((Y-X)/D)
}

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(X, Y, D) {
    // write your code in JavaScript (Node.js 8.9.4)
    return Math.ceil((Y-X)/D)
}