#include<stdio.h>
int main(){
    int x,y;
    int *ptr_x=&x;
    int *ptr_y=&y;
    scanf("%d",ptr_x);
    scanf("%d",ptr_y);
    if(*ptr_x<0||*ptr_y<0){
        printf("Invalid input\n");
    }else{
        printf("%d\n",*ptr_x+ &ptr_y);
    }
    return 0;
    
}