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