package sxv;
import java.util.*;
import java.io.*;
public class test {

	public static void main(String[] args) {
		// TODO 自动生成的方法存根
String a;
double f,y,h,p,re;
String q="log";
String j="/";
String k="^";
String l="*";
System.out.println("符号");
Scanner D=new Scanner(System.in);
a=D.next();
System.out.println("数1");
Scanner t=new Scanner(System.in);
f=t.nextDouble();
System.out.println("数2");
Scanner o=new Scanner(System.in);
p=o.nextDouble();
if (a.equals(q))
{
	ds z=new ds();
	re=z.d(f, p);
}
else if(a.equals(j))
{
	chu chuu=new chu();
			re=chuu.ch(f, p);
}
else if(a.equals(k))
{
	mi mii =new mi();
			re=mii.m(f, p);
}
else
{
	chen chenn=new chen();
			re=chenn.che(f, p);
}
	System.out.println("="+re);
	}

}