#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_reacrant<0 || second_reactant<0){
     printf("Invalid input");
     return 0;
    }
    int total_mass=first_reactant + second_reactant;
    print("%d",total_mass);
    return 0;
}