#coding: utf-8
##yuki_91

a=map(int,raw_input().split())
a.sort()
x,y,z=a
res=x
y=y-x
z=z-x

x=y
y=z
while x>=1 and y>=3:
 res+=1
 x-=1
 y-=3
 if y<x:
  x,y=y,x
res=res+y/5
print res