#include<bits/stdc++.h>
using namespace std;
class rectangle{
private:
int length,width;
public:
rectangle(int x,int y){
length=x;
width=y;
}
void set(int x,int y){
length=x;
width=y;
}
int area(){
return length*width;
}
};
class cuboid:public rectangle{
private:
int height;
public:
// write your code here...
cuboid(int x,int y,int z):rectangle(x,y)//重新构建构造函数
{
height=z;
}
int getvolume()
{
return area()*height;//利用面积函数*高得到体积
}
};
int main(){
int x,y,z;
cin>>x>>y>>z;
cuboid a(x,y,z);
cout<<a.getvolume();
return 0;
}