#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;
}