r,g,b=map(int,input().split())
x=min(r,g,b)
r-=x;g-=x;b-=x
y=(r+g+b)//4
for i in range(max(r,g,b),-1,-1):
  ct=0
  if r>=i:
    ct+=(r-i)//2
  else:
    ct-=(i-r)
  if g>=i:
    ct+=(g-i)//2
  else:
    ct-=(i-g)
  if b>=i:
    ct+=(b-i)//2
  else:
    ct-=(i-b)
  if ct>=0:
    print(x+i)
    exit()