
# coding: utf-8

# In[13]:

a = int(input())
b = int(input())
c = int(input())
p = ((a + b + c)/2)

print((p (p - a)(p - b)(p - c))**0.5)
 


# In[7]:

p = float(3 + 4 + 5/ 2)
print (p)


# In[20]:

a = int(input())
b = int(input())
c = int(input())
p = ((a + b + c) / 2)

s = ((p*(p - a)*(p - b)*(p - c))**0.5)
print (s)


# In[26]:

a = int(input())
b = int(input())
c = int(input())
s = float(p *(p - a)*(p - b)*(p - c))


# In[39]:

a = int(input())
if ((-15) < a <= 12 ) or (14 < a < 17) or (19 <= a );
print('True')
else: 
print('False')


# In[43]:

a = int(input())
print(((-15) < a <= 12 ) or (14 < a < 17) or (19 <= a ))


# In[ ]:



