#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 mas=first reactant+second reactant;
    printf("%d",total mass);
    return 0;
}