v=list(map(int,input().split()))
s=31
for a in range(1,31):
	for b in range(a,31):
		for c in range(b,31):
			d=[31]*31
			d[0]=0
			for i in range(30):
				if i+a<=30:
					d[i+a]=min(d[i+a],d[i]+1)
				if i+b<=30:
					d[i+b]=min(d[i+b],d[i]+1)
				if i+c<=30:
					d[i+c]=min(d[i+c],d[i]+1)
			s=min(s,sum([d[v[i]] for i in range(4)]))
print(s)