#include<stdio.h>
#include<ctype.h>
int main()
{
    int firstreactant,secondreactant,third;
    scanf("%d\n %d\n",&firstreactant,&secondreactant);
    if((firstreactant<0||secondreactant<0||isalpha(firstreactant)||isalpha(secondreactant)))
    {
     printf("Invalid input\n");
    }
    else
    {
     printf("%d\n %d",firstreactant+secondreactant);   
    }
    return 0;
}