a = int(eval(input()))

if a >= 30 :

    print("Yes")

else:print("No")
a = int(eval(input()))

ans = "Yes" if a>= 30 else "No"

print(ans)
a = int(eval(input()))
if a >= 30:
    print("Yes")
else:
    print("No")

a = int(eval(input()))
ans = "Yes" if a >= 30 else "No"
print(ans)

-if a >= 30: -    print("Yes") -else: -    print("No") +ans = "Yes" if a >= 30 else "No" +print(ans)