// editor3
#include<iostream>
using namespace std;

int calculateArea(int i,int w){
    if(l <= 0 || w <= 0 ){
        throw "Invalid input";
    }
    return l * w;
}
int main()
{
    int length,width;
    cin>>length;
    cin>>width;
    try{
        int area = calculateArea(length,width);
        cout << area;
    }
    catch (const char* msg)
    {
        cout<<msg;
    }
    return 0;
}