using System; using System.Collections.Generic; using System.Linq; namespace No407{ public class Program{ public static void Main(string[] args){ var sr = new StreamReader(); //--------------------------------- var N = sr.Next(); var L = sr.Next(); var ps = new List(); var nl = Enumerable.Range(2, (int)L - 1).ToList(); var sqrt = (int)Math.Sqrt(L); while(nl[0] <= sqrt){ var prime = nl[0]; ps.Add(prime); nl.RemoveAll(value => value % prime == 0); } ps.AddRange(nl); Console.WriteLine(ps.Sum(p => Math.Max(L - p * (N - 1) + 1, 0))); //--------------------------------- } } public class StreamReader{ private readonly char[] _c = {' '}; private int _index = -1; private string[] _input = new string[0]; public T Next(){ if(_index == _input.Length - 1){ _index = -1; while(true){ string rl = Console.ReadLine(); if(rl == null){ if(typeof(T).IsClass) return default(T); return (T)typeof(T).GetField("MinValue").GetValue(null); } if(rl != ""){ _input = rl.Split(_c, StringSplitOptions.RemoveEmptyEntries); break; } } } return (T)Convert.ChangeType(_input[++_index], typeof(T), System.Globalization.CultureInfo.InvariantCulture); } public T[] Next(int x){ var ret = new T[x]; for(var i = 0; i < x; ++i) ret[i] = Next(); return ret; } public T[][] Next(int y, int x){ var ret = new T[y][]; for(var i = 0; i < y; ++i) ret[i] = Next(x); return ret; } } }