a, b, c, d = map(int, input().split())
sum = 0count = 0
if a % 7 == 0:sum += acount += 1if b % 7 == 0:sum += bcount += 1if c % 7 == 0:sum += ccount += 1if d % 7 == 0:sum += dcount += 1
if count == 0:print("Нет чисел, кратных 7")else:average = sum / countprint(average)
a, b, c, d = map(int, input().split())
sum = 0
count = 0
if a % 7 == 0:
sum += a
count += 1
if b % 7 == 0:
sum += b
count += 1
if c % 7 == 0:
sum += c
count += 1
if d % 7 == 0:
sum += d
count += 1
if count == 0:
print("Нет чисел, кратных 7")
else:
average = sum / count
print(average)