package N;

import java.util.List;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scan = new Scanner(System.in);
		int i = scan.nextInt();
		switch(i) {
		case 1://计算e^x
			break;
		case 2://计算logax
			break;
		case 3://计算加减乘除
			Scanner scanner=new Scanner(System.in);
			System.out.println("输入表达式：");
			String expression=scanner.next();
			 Calculation  calculation=new  Calculation();
			List<String> rpnList=calculation.InfixtoList(expression);
			List<String> tr=calculation.ListtoSuffix(rpnList);
			int res=calculation.calculate(tr);
			System.out.println(res);
			break;
		case 4://计算三角函数
			break;
		}
	}

}