n = int(input('banyaknya kasus = '))

for i in range (1, n+1) :
    a = int(input('banyaknya kabel = '))
    kabel1 = []
    kabel2 = []
    for j in range (a) :
        x, y = map(int, input().split())
        kabel1.append(x)
        kabel2.append(y)
    titik = 0
    for k in range (a) :
        for l in range (k+1, a) :
            if (kabel1[k] - kabel1[l]) * (kabel2[k] - kabel2[l]) < 0 :
                titik = titik + 1
    print(f"Case #{i} : {titik}")