#Медленный способ
file = open('4A.txt')
A = list(map(int, file.readlines()))
n = A[0]
A = A[1:]
count = 0
for i in range(n):
    for j in range(i + 1, n):
        if (A[i] * A[j]) % 5 == 0 and (A[i] + A[j]) % 2 != 0:
            count += 1
print(count)

#Статический способ
file = open('4B.txt')
A = list(map(int, file.readlines()))
n = A[0]
A = A[1:]
k0_5, k1_5, k0, k1 = 0, 0, 0, 0
for i in range(n):
    x = A[i]
    if x % 5 == 0 and x % 2 == 0:
        k0_5 += 1
    if x % 5 == 0 and x % 2 != 0:
        k1_5 += 1
    if x % 5 != 0 and x % 2 == 0:
        k0 += 1
    if x % 5 != 0 and x % 2 != 0:
        k1 += 1
print((k0_5 * k1_5) + (k0_5 * k1) + (k1_5 * k0))

#Динамичсекий способ
file = open('4B.txt')
A = list(map(int, file.readlines()))
n = A[0]
A = A[1:]
k0_5, k1_5, k0, k1 = 0, 0, 0, 0
count = 0
for i in range(n):
    if A[i] % 5 == 0 and A[i] % 2 == 0:
        count += k1
        count += k1_5
    if A[i] % 5 == 0 and A[i] % 2 != 0:
        count += k0
        count += k0_5
    if A[i] % 5 != 0 and A[i] % 2 == 0:
        count += k1_5
    if A[i] % 5 != 0 and A[i] % 2 != 0:
        count += k0_5

    if A[i] % 5 == 0 and A[i] % 2 == 0:
        k0_5 += 1
    if A[i] % 5 == 0 and A[i] % 2 != 0:
        k1_5 += 1
    if A[i] % 5 != 0 and A[i] % 2 == 0:
        k0 += 1
    if A[i] % 5 != 0 and A[i] % 2 != 0:
        k1 += 1
print(count)