n = input().split()
a = float(n[0])
b = float(n[1])
c = float(n[2])
su = a + b + c
if su >= 200:
    print("%.1f" % (su * 0.8))
else:
    print('%.1f' % (su * 0.9))
/**************************************************************
	Problem: 1624
	User: admin
	Language: Python
	Result: Accepted
	Time:168 ms
	Memory:34480 kb
****************************************************************/