#!/usr/bin/python
# -*- coding: utf-8 -*-

# import
from sys import stdin, setrecursionlimit
setrecursionlimit(10**8)

def int_map():
    return map(int,input().split())

def int_list():
    return list(map(int,input().split()))

def int_mtx(N):
    x = [list(map(int, stdin.readline().split())) for _ in range(N)]
    return x

def str_mtx(N):
    x = [list(stdin.readline()[:-1]) for _ in range(N)]
    return x

def print_space(l):
    return print(" ".join([str(x) for x in l]))



"""    main code    """


a1,a2,a3,b = int_map()

if a1+a2+a3+b > 3*a3:
    print(a1+a2+a3+b)
else:
    print(3*a3)