a, b, c, d=[int(i) for i in input().split()]

first = a + b + c + d 
second = a*3
third = b*3
fourth = c*3

fifth = a*2 + b
sixth = a + b*2
seventh = a*2 +c
eighth = a + c*2
nineth = b + c*2
ten= b*2 +c

select_damage =[first,second,third,fourth,fifth,sixth,seventh,eighth,nineth,ten]

print(max(select_damage))