Problem:
Change-Making Problem

You want to make change for $n$ cents. Assuming that you have infinite supply of coins of 1, 5, 10 and/or 25 cents coins respectively, find the minimum number of coins you need.

Input

$n$

The integer $n$ is given in a line.

出力

Print the minimum number of coins you need in a line.

Constraints

$1 \le n \le 10^9$

Sample Input 1

100

Sample Output 1

4

Sample Input 2

54321

Sample Output 2

2175

Solution in C# (judge verdict: Accepted)

using System;
using System.Linq;
using System.Numerics;
using System.Collections.Generic;
using static System.Math;
using System.Collections;

class P
{
    static void Main()
    {
        var a = int.Parse(Console.ReadLine());
        int res = 0;
        while(a>=25){
            res++;
            a-=25;
        }
        while(a>=10){
            res++;
            a-=10;
        }
        while(a>=5){
            res++;
            a-=5;
        }
        while(a>=1){
            res++;
            a-=1;
        }
        Console.WriteLine(res);
    }
}