using System; using CompLib.Mathematics; using CompLib.Util; public class Program { public void Solve() { var sc = new Scanner(); long a = sc.NextLong(); long b = sc.NextLong(); long gcd = MathEx.GCD(a, b); long ng = 0; long ok = 1000000000; while (ok - ng > 1) { long mid = (ok + ng) / 2; if (mid * mid >= gcd) ok = mid; else ng = mid; } if (ok * ok == gcd) { Console.WriteLine("Odd"); } else { Console.WriteLine("Even"); } } public static void Main(string[] args) => new Program().Solve(); } // https://bitbucket.org/camypaper/complib namespace CompLib.Mathematics { using System; using System.Collections.Generic; #region GCD LCM /// /// 様々な数学的関数の静的メソッドを提供します. /// public static partial class MathEx { /// /// 2 つの整数の最大公約数を求めます. /// /// 最初の値 /// 2 番目の値 /// 2 つの整数の最大公約数 /// ユークリッドの互除法に基づき最悪計算量 O(log N) で実行されます. public static int GCD(int n, int m) { return (int) GCD((long) n, m); } /// /// 2 つの整数の最大公約数を求めます. /// /// 最初の値 /// 2 番目の値 /// 2 つの整数の最大公約数 /// ユークリッドの互除法に基づき最悪計算量 O(log N) で実行されます. public static long GCD(long n, long m) { n = Math.Abs(n); m = Math.Abs(m); while (n != 0) { m %= n; if (m == 0) return n; n %= m; } return m; } /// /// 2 つの整数の最小公倍数を求めます. /// /// 最初の値 /// 2 番目の値 /// 2 つの整数の最小公倍数 /// 最悪計算量 O(log N) で実行されます. public static long LCM(long n, long m) { return (n / GCD(n, m)) * m; } } #endregion #region PrimeSieve public static partial class MathEx { /// /// ある値までに素数表を構築します. /// /// 最大の値 /// 素数のみを入れた数列が返される /// 0 から max までの素数表 /// エラトステネスの篩に基づき,最悪計算量 O(N loglog N) で実行されます. public static bool[] Sieve(int max, List primes = null) { var isPrime = new bool[max + 1]; for (int i = 2; i < isPrime.Length; i++) isPrime[i] = true; for (int i = 2; i * i <= max; i++) if (!isPrime[i]) continue; else for (int j = i * i; j <= max; j += i) isPrime[j] = false; if (primes != null) for (int i = 0; i <= max; i++) if (isPrime[i]) primes.Add(i); return isPrime; } } #endregion } namespace CompLib.Util { using System; using System.Linq; class Scanner { private string[] _line; private int _index; private const char Separator = ' '; public Scanner() { _line = new string[0]; _index = 0; } public string Next() { if (_index >= _line.Length) { string s; do { s = Console.ReadLine(); } while (s.Length == 0); _line = s.Split(Separator); _index = 0; } return _line[_index++]; } public string ReadLine() { _index = _line.Length; return Console.ReadLine(); } public int NextInt() => int.Parse(Next()); public long NextLong() => long.Parse(Next()); public double NextDouble() => double.Parse(Next()); public decimal NextDecimal() => decimal.Parse(Next()); public char NextChar() => Next()[0]; public char[] NextCharArray() => Next().ToCharArray(); public string[] Array() { string s = Console.ReadLine(); _line = s.Length == 0 ? new string[0] : s.Split(Separator); _index = _line.Length; return _line; } public int[] IntArray() => Array().Select(int.Parse).ToArray(); public long[] LongArray() => Array().Select(long.Parse).ToArray(); public double[] DoubleArray() => Array().Select(double.Parse).ToArray(); public decimal[] DecimalArray() => Array().Select(decimal.Parse).ToArray(); } }