n = int(eval(input()))

if n >= 30:

  print('Yes')

else:

  print('No')
n = int(eval(input()))

s = ''

if n >= 30:

  s = 'Yes'

else:

  s = 'No'

print(s)
n = int(eval(input()))
if n >= 30:
    print("Yes")
else:
    print("No")

n = int(eval(input()))
s = ""
if n >= 30:
    s = "Yes"
else:
    s = "No"
print(s)

+s = "" -    print("Yes") +    s = "Yes" -    print("No") +    s = "No" +print(s)