using System; using System.Collections.Generic; class Program { static string InputPattern = "Input5"; static List GetInputList() { var WillReturn = new List(); if (InputPattern == "Input1") { WillReturn.Add("10000"); WillReturn.Add("5"); } else if (InputPattern == "Input2") { WillReturn.Add("24500"); WillReturn.Add("9"); } else if (InputPattern == "Input3") { WillReturn.Add("1000"); WillReturn.Add("6"); } else if (InputPattern == "Input4") { WillReturn.Add("75000"); WillReturn.Add("50"); } else { string wkStr; while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr); } return WillReturn; } static void Main() { List InputList = GetInputList(); ulong N = ulong.Parse(InputList[0]); ulong M = ulong.Parse(InputList[1]); //余った金額 ulong RestVal = N % (1000 * M); Console.WriteLine(DeriveCombiCnt(M, RestVal / 1000)); } //Aつの袋からBつの袋を選ぶ組み合わせの数を求める static ulong DeriveCombiCnt(ulong pA, ulong pB) { if (pA == 0) return 1; pB = Math.Min(pB, pA - pB); var ProdList = new List(); var DeviList = new List(); ulong WillReturn = 1; for (ulong I = pA; I >= pA - pB + 1; I--) { ProdList.Add(I); } var DevList = new List(); for (ulong I = 1; I <= pB; I++) { DeviList.Add(I); } while (ProdList.Count != 0 && DeviList.Count != 0) { if (ProdList.Count != 0) { WillReturn *= ProdList[0]; ProdList.RemoveAt(0); } for (int I = 0; I <= DeviList.Count - 1; I++) { if (WillReturn % DeviList[I] == 0) { WillReturn /= DeviList[I]; DeviList.RemoveAt(0); break; } } } return WillReturn % 1000000000; } }