#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;
}