queen

int main(){
    int x1, x2, y1, y2;
     while(scanf("%d %d %d %d", &x1, &x1, &y1, &y2)>0){
        if(x1 == 0 && x2 == 0 && y1 == 0 && y2 == 0) return 0;
        if(x1 == x2 && y1 == y2) printf("0\n");
        else if(x1 == x2 || y1 == y2) printf("1\n");
        else if(abs(x1 - x2) == abs(y1 - y1)) printf("1\n");
        else printf("2\n");
    }
    return 0;
}