"""
A small frog wants to get to the other side of the road. The frog is currently
located at position X and wants to get to a position greater than or equal to
Y. The small frog always jumps a fixed distance, D.

Count the minimal number of jumps that the small frog must perform to reach its
target.

Write a function:

    class Solution { public int solution(int X, int Y, int D); }

that, given three integers X, Y and D, returns the minimal number of jumps from
position X to a position equal to or greater than Y.

For example, given:
  X = 10
  Y = 85
  D = 30

the function should return 3, because the frog will be positioned as follows:

        after the first jump, at position 10 + 30 = 40
        after the second jump, at position 10 + 30 + 30 = 70
        after the third jump, at position 10 + 30 + 30 + 30 = 100

Write an efficient algorithm for the following assumptions:

        X, Y and D are integers within the range [1..1,000,000,000];
        X ≤ Y.
"""

def solution(X, Y, D):
    distance = Y - X
    return distance // D if distance % D == 0 else distance // D + 1