#include<stdio.h>
int main()
{
    int first_reactant,seconf_reactant;
    if(scanf("%d",&first_reactant) !=1||
    scanf("%d",&second_reactant) !=1)
    {
        printf("Invalid input");
        return 0;
    }
    if(first_reactant<0||second_reactant<0)
    {
        printf("Invalid input");
        return 0;
    }
    int total_mass=first_reactant+second_reactant;
    printf("%d",total_mass);
    return 0;
}