class Tx:
    def __init__(self,c,k,g):
        self.c=c
        self.k=k
        self.g=g
        self.s=(c+k)*g/2
    
n=int(input())
list1=list()
for i in range(n):
    c,k,g=list(map(int,input().split()))
    list1.append(Tx(c,k,g))

list2=sorted(list1,key=lambda t:(-t.s))
print(list2[0].s)

/**************************************************************
	Problem: 1330
	User: admin
	Language: Python
	Result: Accepted
	Time:91 ms
	Memory:34480 kb
****************************************************************/