#include<stdio.h>
int main() {
int first_reaction;
int second_reaction;
    scanf("%d ",&frist_reaction);
    scanf("%d",&second_reaction);
    if frist_reaction < 0 or second_reaction < 0:
    printf("Invalid input")
    else:
    total_mass = frist_reaction + second_reaction
    print(total_mass)
    return 0;
}