#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;
}