def calc(stone)
    
    return stone[0] + calc(stone.map{|e| e-stone[0]}) if (stone[0]!=0)
    
    k = [(stone[2]-stone[1])/2,stone[1]].min
    return k + calc([0,stone[1]-k,stone[2]-k*3].sort!) if 0<k
    
    k = [stone[1]/4,stone[2]/4].min * 2
    return k + calc([0,stone[1]-k*2,stone[2]-k*2].sort!) if 0<k
    
    k = stone[2]/5
    return k + calc([0,stone[1],stone[2]%5].sort!) if 0<k
    
    return k + calc([1,stone[1],stone[2]-2].sort!) if 3<=stone[2]
    
    return 0
    
end

r,g,b = gets.split.map(&:to_i)

p calc([r,g,b].sort)