#include<stdio.h>
int main()
{
    int first_reactant;
    int second_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;
    
}