Light OJ 1202

#include<stdio.h>
#include<math.h>
int main()
{
    long long int t,i,x,y,x1,y1,x2,y2;
    scanf("%lld",&t);
    for(i=1;i<=t;i++){
        scanf("%lld %lld %lld %lld",&x1,&y1,&x2,&y2);
        printf("Case %lld: ",i);
        x=abs(x1-x2);
        y=abs(y1-y2);
        if(x==y)
            printf("1\n");
        else if(x%2==y%2)
            printf("2\n");
        else
            printf("impossible\n");
    }
    return 0;
}