#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;
}