老人家的舊書房

import java.io.*;

public class ex5_2{
public static void main(String[] argv)
throws IOException{

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("請輸入成績：");
String str = br.readLine();
int i = Integer.parseInt(str);
if(90 System.out.println("A等");
}
else if(80 System.out.println("B等");
}
else if(70 System.out.println("C等");
}
else if(60 System.out.println("D等");
}
else{
System.out.println("E等");
}
}
}