#include<stdio.h>
int main()
{
    int reactant 1,reactant 2;
    if(scanf("%d%d",&reactant1,&reactant2)!=2)
    {
        printf("Invalid input");
        return 0;
    }
    if(reactant1<0||reactant2<0)
    {
        printf("Invalid input"):
    }
    else
    {
        int total=reactant1+reactant2;
        printf("%d",total);
    }
    return 0;
}