r,g,b=map(int,input().split())
x=min(r,g,b)
r-=x;g-=x;b-=x
y=(r+g+b)//4
f=0
if (r==0 and max((g-y)//2,0)+max((b-y)//2,0)<y) or (g==0 and max((r-y)//2,0)+max((b-y)//2,0)<y) or (b==0 and max((r-y)//2,0)+max((g-y)//2,0)<y):
  f=1
if (r==0 and g==0) or (g==0 and b==0) or (r==0 and b==0):
  print(x+(r+g+b)//5)
  exit()
print(x+(r+g+b)//4-f)