#include<stdio.h>
int main()
{
int first_reactant,second_reactant;
scanf("%d",&first_reactant);
scanf("%d",&second_reactant);
if(first_reactant<0&&second_reacant<0){
    printf("Invalid input");
}
else{
    printf("the total mass products:%d",first_reactant+second_reactant);
}
return 0;
}