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