#include<stdio.h>
intb main()
{
    int X,x;
    int Y,y;
    int Z,z;
    scanf("%d %d",&X,&x);
    scanf("%d %d",&Y,&y);
    scanf("%d %d",&Z,&z);
    if(X<0 || x<0 || Y<0 || y<0 || Z<0 || z<0)
    printf("Invalid input");
    else
    printf("%d",)
}