import sys
input=lambda: sys.stdin.readline().rstrip()
v0,v1,v2,v3=map(int,input().split())
import itertools
ans=float("inf")
for A in itertools.combinations(range(1,31),3):
  D=[float("inf")]*31
  D[0]=0
  for i in range(1,31):
    for a in A:
      if i>=a:
        D[i]=min(D[i],D[i-a]+1)
  ans=min(ans,D[v0]+D[v1]+D[v2]+D[v3])
print(ans)