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