#include<stdio.h>
int main()
{
    int a,b;
    if(scanf("%d",&a) != 1 || scanf("%d",&b) != 1)
    {
        printf("Invalid Input");
        return 0;
    }
    if(a<0 || b < 0)
    {
        printf("Invalid Input");
    }
    else
    {
        printf("%d",a+b);
    }
    return
}