#include<stdio.h>
int main()
{
    int firstreactant,secondreactant,sum;
    scanf("%d %d",&firstreactant,&secondreactant);
    sum =firstreactant+secondreactant;
    if(sum>0 && sum!<=0)
    {
        printf("%d",sum);
    }
    else
    {
        printf("Invalid input");
        return 0;
    }
    return 0;
}