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