#include <stdio.h>
#include <stdlib.h>
int f(int);
void main(int argc, char *argv[]) {
  printf("%d\n", f(atoi(argv[1])));
}
int f(int n) {
  if(n < 1) { return 1; }
  else      { return n * f(n-1); }
}

import java.util.*;
public class Sam11 {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.print("s1> "); String s1 = sc.nextLine();
    System.out.print("s2> "); String s2 = sc.nextLine();
    double d1 = Double.parseDouble(s1);
    double d2 = Double.parseDouble(s2);
    System.out.println("sum: " + (d1+d2));
  }
}

class Dog {
  String name;
  double speed = 0.0;
  public Dog(String n) { name = n; }
  public String toString() { return "name="+name+" speed="+speed; }
  public String getName() { return name; }
  public double getSpeed() { return speed; }
  public void addSpeed(double d) { speed += d; }
}

import java.util.*;
import java.io.*;

public class Sam12 {
  public static void main(String[] args) throws Exception {
    Toknizer tok = new Toknizer(args[0]);
    Scanner sc = new Scanner(System.in);
    while(true) {
      System.out.print("> ");
      String line = sc.nextLine();
      if(line.equals("p")) {
        System.out.println(tok.curTok());
      } else if(line.equals("e")) {
        System.out.println(tok.isEof());
      } else if(line.equals("f")) {
        tok.fwd(); System.out.println(tok.curTok());
      } else if(line.equals("q")) {
        System.exit(0);
      }
    }
  }
}
class Toknizer {
  Scanner sc;
  String tok;
  boolean eof = false;
  public Toknizer(String fname) throws Exception {
    sc = new Scanner(new FileInputStream(fname)); fwd();
  }
  public boolean isEof() { return eof; }
  public String curTok() { return tok; }
  public void fwd() {
    if(!eof && sc.hasNext()) { tok = sc.next(); }
    else { eof = true; tok = "$"; }
  }
}