import math
a = eval(input())
b = eval(input())
c = eval(input())
p = (a+b+c)/2
if a + b > c and a + c > b and b + c > a:
print('YES')
print('{:.2f}'.format(math.sqrt(p*(p-a)*(p-b)*(p-c))))
else:
print('NO')
lua:
local access_token = ngx.var.cookie_SGAccessToken
if access_token then
ngx.header["Set-Cookie"] = "SGAccessToken="..access_token.."; path=/;Max-Age=3000"
end