#include<iostream>
#include<string>
using nmaespace std;

int main(){
    strings1,s2;
    if(!(cin>>s1>>s2))return 0;
    
    try{
        long long w=stoll(s1),h=stoll(s2);
        if(w>0 && h>0)cout<<w*h;
        else cout<<"Invalid input";
    }catch(...){
        cout<<"Invalid input";
    }
    return 0;
}