#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, width;
    cin >> length;
    cin >> width;
    
    try{
        int area = calculateArea(length, width);
        cout << area;
    }
    catch(const char* msg){
        cout << msg;
    }
    return 0;
}