我想求长方形的体积，程序不知道哪里错了，请高手指点import java.util.Scanner;

public class Fi {
public static int area(int a,int b,int c){
return(a*b*c);

}

public static void main(String[]args){
int tiji;
System.out.println("请输入长方形的长度");
Scanner in = new Scanner(System.in);
int str = in.nextInt();
System.out.println("请输入长方形的宽度");
Scanner on=new Scanner(System.in);
int str1=on.nextInt();
System.out.println("请输入长方形的高");
Scanner ou=new Scanner(System.in);
int str2=ou.nextInt();
tiji=area(in,on,ou);
System.out.println("长方形的体积是"+tiji);


}

}