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