package main

import (
	"fmt"
	"math"
)

func c(x, r, b, g int) bool {
	shortage:=max(0, x-r)+max(0,x-b)+max(0,x-g)
	r = max(0, r-x)/2*2
	b = max(0, b-x)/2*2
	g = max(0, g-x)/2*2
	if shortage*2 <= r+b+g{
		return true
	}else{
		return false
	}
}

func main() {
	var R, G, B int
	fmt.Scan(&R, &B, &G)
	lb := -1
	ub := 10000000
	mid := 0
	for ub-lb>1{
		mid=(lb+ub)/2
		if c(mid, R, G, B){
			lb = mid
		}else{
			ub = mid
		}
		//mt.Println(lb, ub, mid)
	}
	fmt.Println(ub-1)
}

//////////////////////////////////////////////////////
func min(a, b int) int {
	return int(math.Min(float64(a), float64(b)))
}

func max(a, b int) int {
	return int(math.Max(float64(a), float64(b)))
}