// editor4
#include<iostream>
using namespace std;
class bank(
    public;
    int total(int a, int b){
        return 0;
    }
};
int main(){
    int a,b;
    cin>>a>>b;
    if(a<0 || b<0){
        cout<<"invalid input";
        return 0;
    }
    bank obj;
    cout<<obj.total(a,b);
    return 0;
}