s=input().split()
x=int(s[0])
y=int(s[1])
z=int(s[2])
a=x*0.2+y*0.3+z*0.5
print(int(a))
/**************************************************************
	Problem: 1565
	User: admin
	Language: Python
	Result: Accepted
	Time:424 ms
	Memory:34244 kb
****************************************************************/