from heapq import heappush, heappop, heapify
import sys
from collections import defaultdict, deque,Counter
from math import ceil, floor, sqrt, factorial,gcd
from itertools import permutations, combinations,product
from bisect import bisect_left, bisect_right
from copy import deepcopy
from functools import lru_cache #@lru_cache(maxsize=None)
from fractions import Fraction
from copy import deepcopy
sys.setrecursionlimit(10**6)
# input = sys.stdin.readline
vector1 = [[0, -1], [1, 0], [0, 1], [-1, 0]]
vector2 = [[0, 1], [1, 0], [-1, 0], [0, -1],
           [1,-1], [-1, 1], [1, 1], [-1, -1]]




def main():
    
    a,b,c,ab = map(int,input().split())
    
    
    print(c + max(a+ab,b+ab))
    
    
    


if __name__ == '__main__':
    main()