using System; using System.Collections.Generic; using System.IO; using System.Linq; public class Program { public static void Main() { var so = new Solver(); //var so = new Solver("input.txt", "output.txt"); so.Solve(); } } public class Solver { private readonly Reader reader; private readonly TextWriter writer; public Solver() { reader = new Reader(Console.In); writer = Console.Out; } public Solver(string input, string output) { reader = new Reader(new StreamReader(input)); writer = new StreamWriter(output); } public void Solve() { decimal mod = (decimal)Math.Pow(10, 12); decimal N = reader.RInt(); decimal s = 1; bool isOver = false; for (decimal i = 1; i <= N; i++) { s = s * i; if (isOver && s == 0) { break; } else if (s >= mod) { isOver = true; s = s % mod; } } if (isOver) { writer.WriteLine(s.ToString().PadLeft(12, '0')); } else { writer.WriteLine(s.ToString()); } writer.Flush(); } } public class Reader { private readonly TextReader reader; private readonly char separator = ' '; private string[] A = new string[0]; private int i; public Reader(TextReader r) { reader = r; } public string String() { return Set(); } public int Int() { return int.Parse(Set()); } public long Long() { return long.Parse(Set()); } public decimal Decimal() { return decimal.Parse(Set()); } public string RString() { return RSet(); } public int RInt() { return int.Parse(RSet()); } public long RLong() { return long.Parse(RSet()); } public decimal RDecimal() { return decimal.Parse(RSet()); } public int[] RIntArray() { Read(); return A.Select(x => int.Parse(x)).ToArray(); } private void Read() { string line = reader.ReadLine(); A = line.Split(separator); i = 0; } private string Set() { return A[i++]; } private string RSet() { Read(); return A[i++]; } }